It seems that lately when I reply to forum topics, I'll type my reply using Rich Text, no special formatting, just normal text and when I click Post it will tell me to "correct errors" and that it removed invalid HTML, even though I didn't put any HTML in or even used any formatting features. If I then go into HTML view, I'll find the end of my post contains many blank lines at the end (<p> </p> repeated many times). I edit those out and click post and then it works.
I use the Brave Browser on iPadOS 16.4.1 to post here. I turned Brave Shields off for this site to type this post, to see if it's browser related. I could try Safari as well. I used to use Firefox on Windows but ever since they switched to 2FA I only use my iPad to log in here since the 2FA only remembers one device.
I'm about to click post, let's see what happens here. I'll reply with findings.
Initial post worked fine. Now typing a reply to see what happens.
Typing more.
Typing more.
This is only a test.
Clicking Post now.
Editing post. Issue didn't happen. Maybe Brave shields were breaking the site?