Feedback by Toby helped me fix the issue. I increased the number of links to 6 and this is now working.
“Hi there,
I think the problem might be as in the other thread I’ve just updated. Buddypress have fixed a bug in the core moderation function which means that unless you’ve upped the default number of links, activity updates containing 2 or more links are not added to the activity stream and no error message is given.
By default, links using a thumbnail, videos, or documents will have at least 2 links. This is why clicking ‘no thumbnail’ makes it work again.
Try upping the number of links allowed in Admin > Settings > Discussion. Please note that this number is >= (i.e. if you want to allow 3 links, set the number to 4 etc.)”
