Yeah, personally, I am not the biggest fan of Zorin Connect, I think it needs a lot of work. I am able to use it to do stuff like copy to clipboard, transfer files between phone and computer.
But when I need to be able to read a send RCS message to my phone, via my computer, my computer is not able to read any messages, short of a notification bubble. Additionally, I can't even get the normal mode to work at all in Zorin Connect.
The normal mode, lists everything, from not only current people in my contact list, but olds ones which should never be there, cause I don't speak to them anymore, its a hodge podge of bs, which forces me to use legacy mode.
And even in legacy mode, where it only shows my contacts properly, (which is a good thing) but it still won't let me read incoming messages beyond a notification bubble, even if I have enabled permissions to do so.
The most I can do computer side, is send a text message to somebody on my cantact list, but in legacy mode, as soon as you send the message, there is no confirmation computer side, only the phone shows confirmation, and shows the whole chat.
Zorin connect is heavily underwhelming for me. I gave up on trying to make it work, with 2 different phones so far. It has nothing to do with my phone, it has everything to do with Zorin Connect just not being ready for prime time.
I enjoy using it mostly for copying links to clipboard, so I can share a video I am watching on YouTube, to somebody on my phone, thats the most real usage I am getting out of it. Yes, I've heard KDE Connect is better, but I just say forget it for me.
I can pick up my phone like a normal person, and check my messages and answer them like a normal person. I don't need to have full integration with my phone to my computer, it really isn't necessary.
Anyways, thats been my experience, which you are confirming as well with your post.