There are errors in menu display or Collabora connection on smartphone

I have limited use of my NC. For the first time, most users got together and had the opportunity to use NC. So I noticed some anomalies.

Various menus (Activity, Comments, Chat, Versions, Sharing) in the details panel (right side panel) of each data in “File”.

All users saw the same file (shared). “Comment” is displayed for some users, but “Chat” is not displayed. Or the reverse combination. I don’t specify group restrictions in Talk. Some users did not have a “version”. Each user restarted the device or re-logged in the NC did not improve. I looked at the logs at that time and found no errors in the logs.
I only banned “reshare” in the sharing settings, and everyone was editable.

This is the first time I have seen each user’s usage sight, so I don’t know when this phenomenon started.

Collabora files are treated as data.

I use Collabora, but only a few users could not connect to Collabora. Their behavior was when the Collabora Online NC’s app was not installed on NC. Whether it downloads or not.
I have no group settings in Collabora. I deliberately set up groups in Collabora, but things did not change.
The device of the user who could not connect was the iPhone(iOS13.3, Safari).
They were amateurs and had no special settings such as content blocks. They couldn’t connect to Collabora after restarting or logging in the device.
At that time, 8 people were trying to open Collabora file (not the same file). Is this a bug due to server performance? Or is Collabora itself limited in number?

CentOS 7.7, PHP 7.3.14, Nginx 1.16.1, MariaDB 10.2.29, Nextcloud 18
User device: Safari on iPhone(iOS 13.3), Chrome on Android