Warning: conversion to 5.8 deleted my widgets.

I just visited 4 of my sites that auto-updated to WordPress 5.8 and noticed that 2 of them had footer widgets missing. I then went into admin and when going to the widgets area was greeted by the message and tour that widgets had been converted to using blocks. After that completed it looks like it had converted my 4 widgets to use blocks but 2 of the widgets now just show a blank block. This makes me think that somehow there was a problem and they got removed during the conversion. I ended up going to archive.org to look at a previous snapshot of the site to determine the content removed in the blocks that were converted. I’ll now need to re-build those using blocks. Not the end of the world but a little annoying. I wanted to share this in case others run into this issue which I hadn’t seen mentioned.