How long has it been since the chat archive was cleared? The chat pane gets wonky when the archive gets too large. Have the GM clear the chat archive and see if that clears up the issue. If so, let us know. If not, it is time to start troubleshooting. Everyone affected will need to please follow Steps 1-3
of our Solving Technical Issues checklist (confirm you're using the latest non-test version of Firefox or Chrome; turn off all extensions, addons, and anti-virus; and clear your cache) to see if
one of those components is causing the problem. We can only help if we
can recreate your issue, so it is important that you follow each step. If doing that fixes the issue, just let us know. Otherwise, move on to Step 4 , and we'll need all that information for each affected person, in addition to a link to the game (in the form of <a href="https://app.roll20.net/campaigns/details/xxxxxx/" rel="nofollow">https://app.roll20.net/campaigns/details/xxxxxx/</a> , not a join link) to further assist you.