What exactly makes you think it is “removing itself from your system”? This is highly unlikely.
Many other things are likely, most commonly caused by router issues. Please describe your network.
Because it doesn’t appear in my system and I have a prompt to add my Sonos One SL. So I add it (again) and it shows in my system, but then some time later (sometimes on a weekly basis), it no longer shows in my system and I have the prompt (again) to add it.
All of my speakers are on the same wifi network which has great coverage across each location they are situated.
Next time it is gone submit a diagnostic and note the number.
Power down all Sonos and reboot the router, power up the Sonos and send another diagnostic.
If the speaker is still missing call Sonos with both the diagnostic numbers and see if they can see an issue using the internal data hidden from us users.
If the speaker comes back it might be an IP address issue, assign all Sonos a fixed/static IP address from your router’s DHCP Settings page. Do the power down, reboot power up and hopefully the issue will not bite you again. If it does at least the IP issue is off the possible problems list.