Hi Brother @Allen Wayne, do you have the posting tool bar just above where we post? On my posts there is the letter T with an up and down arrow fifth from the left that allows increasing of decreasing the font size with selections of one through seven. Clicking on it I don't see options that remain, and I think and change returns to the size 4 after every post. I'm going to attempt look at my profile and see if there may be something there dealing with font sizes.
Hi again. I got tied down in cleaning a thread, but I didn't find anything in the preferences, but I know there are things on our personal computer affecting what we see things too; at least I think there are.
Consider doing a system restore to an earlier time, and I would start off by choosing the latest one offered. You may have accidently hit something since your last update that changed something, and this will simply eliminate it.
If you've never done it simply go to your help and type in Restore to an earlier time, or system restore, or something like that depending which program you're operating with. For instance I use Window 7 Pro.
I've used this a few times to correct my mistakes or theirs, and it has kept me out of the repair shop near every time.