I don't know where you got that idea.
In 1 Peter 1:10-12, 3:18-20, we are told who Jesus "preached to" by the Spirit.
"Of which salvation the prophets have enquired and searched diligently, who prophesied of the grace that should come unto you:
11 Searching what, or what manner of time the Spirit of Christ which was in them did signify, when it testified beforehand the sufferings of Christ, and the glory that should follow."
And..."For Christ also hath once suffered for sins, the just for the unjust, that he might bring us to God, being put to death in the flesh, but quickened by the Spirit:
19 By which also he went and preached unto the spirits in prison;
20 Which sometime were disobedient, when once the longsuffering of God waited in the days of Noah, while the ark was a preparing, wherein few, that is, eight souls were saved by water."
Those prophets and people are in the grave/prison until Jesus returns.
He preached by the Spirit to them, before they died.
The key to understanding this is "by the Spirit".
If Jesus was doing any preaching in hades or wherever some like to think, it would have said "He preached" without adding "by the Spirit".
That would be an strong argument, IF your translation of the Greek weren't debatable. A literal translation destroys your "by the Spirit" point. Here are the possibilities found in Exegetical Summaries. It lists Lexicons, Bibles and Commentaries that differ from each other in [BRACKETS]:
3:19 in which a also having-gone b he-preachedc to the spirits in prison, d
LEXICON—a. ἐν ᾧ (BAGD I.11.c p. 585): ‘in which’ [BNTC; NRSV], ‘by which’ [KJV], ‘through whom’ [NIV], ‘in the spirit’ [NIC; NJB, REB], ‘in that state’ [WBC], ‘it was in the spirit that’ [NAB], ‘in his spiritual existence’ [TEV], not explicit [CEV, NLT].
b. aorist pass. (deponent = act.) participle of πορεύομαι (LN 15.10): ‘to go’ [BNTC, LN, NIC, WBC; all versions except CEV], not explicit [CEV].
c. aorist act. indic. of κηρύσσω (LN 33.256) (BAGD 2.b.β. p. 431): ‘to preach’ [BAGD, LN, NIC; all versions except NRSV, REB], ‘to proclaim’ [BAGD], ‘to make proclamation’ [BNTC, WBC; NRSV, REB].
d. φυλακή (LN 7.24) (BAGD 3. p. 867): ‘prison’ [BAGD, BNTC, LN, NIC; all versions except REB, TEV], ‘refuge’ [WBC]. The phrase ἐν φυλακῇ is translated ‘imprisoned’ [REB, TEV].
QUESTION—What is the meaning of ἐν ᾧ ‘in which’ and what is the antecedent to which it refers?
1. It refers to πνεύματι.
1.1 It means as a spirit or spiritual being [EGT, TG, TH]. It means in his spiritual mode of existence or in the spiritual realm [Alf, BNTC, IVP, NIBC, NIC, TNTC; NAB, NJB, REB, TEV, TNT].
1.2 It means through the instrumentality of the Holy Spirit [NTC; KJV, NIV].
2. It refers to ζῳοποιηθεὶς δὲ πνεύματι ‘made alive in the Spirit’ and means in his risen state [WBC].
3. It refers to the whole process of the passion and resurrection of 3:18 and means ‘in the course of which’ [Sel].
QUESTION—What relationship is indicated by καί ‘also’?
1. It introduces another activity of Christ ‘in the spirit’, in addition to being resurrected [BNTC, NIBC, TNTC].
2. It means ‘even’ [Sel, WBC]: Christ even went to the spirits in prison.
3. It indicates sequence [NTC]: it was after the resurrection that Christ went and preached.
QUESTION—Who are the spirits he is referring to?
1. They are the spirits of the people of Noah’s generation [Alf, ICC, TG, TNTC; NJB, TEV].
2. They are supernatural beings.
2.1 They are fallen angels [NTC].
2.2 They are the fallen angels of Genesis 6:1–4 who married human women and had offspring by them [BNTC, EGT, IVP, NCBC, NIBC, NIC, Sel].
2.3 They are evil spirit beings who are the spiritual offspring of the fallen angels of Genesis 6:1–4 who married human women and had offspring by them [WBC].
QUESTION—What was the nature of the preaching?
1. It was a proclamation of Christ’s victory over the spiritual forces of darkness [BNTC, IVP, NIC, NTC, Sel, WBC].
2. It was evangelistic preaching urging repentance and offering forgiveness.
2.1 Christ was evangelizing the fallen angels [EGT, NCBC].
2.2 Christ was evangelizing people who had died [Alf, ICC, TG].
2.3 It was when the preincarnate Christ preached through Noah to the people of Noah’s day [TNTC].
QUESTION—What is the prison, and where is it located?
1. It is the region of the dead [ICC]. It is that place of the dead known as Sheol in the OT or Hades in the NT [Alf, EGT, NIBC, Sel, TG].
2. It was the place where the spirits of fallen angels are bound in the underworld [NCBC].
3. It was a haunt of evil spirits where they attempted to take refuge [WBC].
4. It is a prison in the heavens [IVP]. It is a strata in the plurality of the heavens in the upper regions [BNTC].
5. It is hell [TNTC].
QUESTION—When did Christ preach?
1. He preached between the crucifixion and the resurrection [EGT, NCBC, Sel, TH].
2. He preached between the crucifixion and the ascension [ICC].
3. He preached after the resurrection [IVP, NIC, NTC, WBC].
4. He preached at the time of the ascension [BNTC].
5. During the time of Noah the preincarnate Christ preached through Noah to Noah’s contemporaries [TNTC].
Abernathy, D. (2008). An Exegetical Summary of 1 Peter (2nd ed., pp. 136–138). SIL International.
I interpret Christ's human spirit was "quickened, strengthened, infused with life" by the Holy Spirit and while "in the Spirit" protecting it from the fires of Hades and the Abyss, He went and preached to the spirits in prison.
Two points to consider.
1) Christ did no sin therefore He didn't deserve any torment so it is right to shield Him from the fire.
2) Christ is appearing as a conquering preacher of righteousness, His human spirit should be clothed with the Divine Presence, Shekhina Glory.
So, while strengthened/protected/Glorified by the Holy Spirit Christ's human spirit went and preached to the spirits in prison, which is somewhere in Hades/Sheol.
18 because also Christ once for sin did suffer -- righteous for unrighteous -- that he might lead us to God, having been put to death indeed, in the flesh, and having been made alive in the spirit,
19 in which also to the spirits in prison having gone he did preach, (1 Pet. 3:18-19 Young's Literal Translation)
18 Because Christ also suffered for sins once, the righteous for the unrighteous, that he might bring us to God; being put to death in the flesh, but made alive in the spirit;
19 in which also he went and preached unto the spirits in prison, (1 Pet. 3:18-19 ASV)
That fits the literal Greek and the OT concept of human spirits getting weak or revived by the Divine Spirit.
The Son is in two natures, fully God and fully human. None of this is about His divine nature.
But I have provided you with all the possibilities so you can study it further.