What is the problem?
Is it possible to connect to octoprint server from different clients at the same time?
What did you already try to solve it?
tryed to connect from Win10 / firefox and at the same time from ipad with firefox or Octoshell
Have you tried running in safe mode?
Did running in safe mode solve the problem?
You can download this in OctoPrint's System Information dialog ... no bundle, no support!)
Additional information about your setup
OctoPrint version, OctoPi version, printer, firmware, browser, operating system, ... as much data as possible
My experience is that connecting from multiple devices is not an issue. I have used both my phone and laptop at the same time without any issues. I a lot fo the time have more than one browser window open on the same machine for the same octoPrint instance.
You say you tried but you do not list what your results were. The assumption is that it failed. But how did you test it? More info is needed to understand your request / Issue.
Two clients for OctoPrint running on a RasPi is not that problem.
The more clients there are, the more load the server (OctoPrint) has to handle.
For more than 3 clients, I would recommend more powerful hardware
This seems to be the problem: I run Octopi on an RP Mod B Rev 2 which is probably not capable for this load.