The issues are a bit more extensive than that. I'll try to make them clear here.
1. When I compose a post, and hit Reply, no matter whether I used a tag in it or not, I always get the "Invalid HTML, correct the highlighted errors" pop-up. There is nothing highlighted.
2. When I hit Reply again, I get the "Leave page?" pop-up. If I click on that, my post then posts.
3. If I put a tag at the beginning, when I hit Reply, the entire post disappears from the reply box, except for the tag.
4. If I put the tag at the end, the post remains. If I tag more than one poster, when the post posts, only the first tag is there.
5. Every time I hit the back browser, or click the page numbers to move onto another page, I get the "Leave page? Changes you made may not be saved" pop-up. I have to click on that to proceed.
6. If I add an emoji, no matter where in the post I put it, it always shifts to the end of the post when it posts.
7. I cannot answer any DMs at all but Katie's. Always get the "Invalid HTML". If I hit Reply again, it does it again, until it says I've tried too many times.
All this is when working in Chrome on desktop. I use the latest version of Chrome. It's been going on for over 2 weeks now.
All works fine in Firefox, but that isn't my preferred browser.
@Katie