See my comments below please:
1) I've just check una.io on both (Lucid) templates and don't see the problem. You may see browser and Android version in attachment. So, in you case it may be cache problem, try please to clear the cache via Studio.
2) I am not sure that I understand. If you mean you can not click back button to open previous chats, then by default there is standard back button on devices should and redirect you to the chats list.
3) It also can be connected with cached js code or may be Jot Server is no connected. Is it possible for me to test it on your site?
4) It is also can be because of cache problem.
Anyway to reproduce the problem, it would be better to test it on your site if you don't mind.