I'm on Sonoma 14.6.1 and this problem still persists. The above have not worked for me. For clarity, mine is a group chat. When I tried the "preview" solution and select messages and it starts a new message altogether, but when I type the name of the group text, it defaults back to the group itself, without keeping the preview item (and there is still no text box). I cannot react to any of the messages in the group chat (i.e., there is no Tapback option). I can apparently delete and start a new text thread, but then I lose all of our previous conversation topics, which is a shame and pretty annoying. This is the second time this has happened for me. Additionally, I will say I use iCloud to share messages across an iPhone 13Pro and a "gently used" MacBook Air, early 2015 running Monterey 12.7.5 (and running quite well, I might add!). Love the products, just this quirky issue has been a pain in my side. ;) Thanks in advance for any thoughts.