I think it just happened today because I remember seeing the weird stuff yesterday.
I have been using the form enhancer by FReeper cynwoody, which fixes the script problem but still is a blessing, and I think should be standard, but for this you need to be using the GreaseMonkey script. Also helpful is the Firefox/PaleMoon/Waterfox extension BBCodeXtra, if you want to make custom scripts.
Thank God for such helps and those who provide them!