package management - How to remove older version of OBS?

I have 2 versions of OBS in my Ubuntu 18.04 LTS.

One is OBS 21.0.2.-modified (or obs-studio --candidate), other is OBS studio 24.00.

The problem is when i installed the newer version, i didn't get just an upgrade from 21.0.2. to 24.00, i got TWO snaps at the same time.
Probably coz candidate version was in different branch of snap development or something.
Not a big deal, but...

The biggest problem is that now both versions can't work right and both miss some functionality.
For instance, 24.00 don't show up in tray (which is a life saver during busy broadcast).
Also when i chose OBS Studio icon (which is obviously 24.00, coz 21.02 was just "OBS"), only 24.00 version is launched! At that moment i can see how one version interfere with another in tray, which is hillarious).
I double checked what version is in tray, and it was exactly 24.00.

(What is weird, also, that built-in Ubuntu software manager can't see V24. Ubuntu Software center can't see it too. Snapcraft site by Canonical can't find it also. It can only be found by clicking direct link in Snapcraft but that's beside the point.)

Logical thing would be delete the old version in terminal BUT... when i use "sudo apt-get remove obs-studio", BOTH version are deleted.
When i use "sudo apt-get remove obs-studio 21.0.2-modified", or "sudo apt-get remove obs-studio --candidate", or just "sudo apt-get remove obs", Ubuntu can't understand the command or tell me that "OBS is not installed".
I used "purge" but with the same result.

I used snap managers like Stacer and Synaptic.

(I can clarify that OBS is a snap, you can see it for yourself - heresnapcraft.io/obs-studio and here (Stacer clearly shows OBS in a Snap category)

Also Synaptic surely works with OBS and shows both versions but calls it "packages".
picture of Synaptic showing me two versions
By snap manager i mean this one piece of software github.com/oguzhaninan/Stacer.)

First one can see nothing but 24.00.
Second one sees older version but somehow can only INSTALL it, but no unistall option!
When i try to use "uninstall completely" in Synaptic it can only see 24.00.

Using apt policy obs-studio i get this

apt policy obs-studio
obs-studio:
  Установлен: 24.0.0-0obsproject1~bionic
  Кандидат:   24.0.0-0obsproject1~bionic
  Таблица версий:
 *** 24.0.0-0obsproject1~bionic 500
        500 http://ppa.launchpad.net/obsproject/obs-studio/ubuntu bionic/main amd64 Packages
        100 /var/lib/dpkg/status
     21.0.2+dfsg1-1 500
        500 http://ru.archive.ubuntu.com/ubuntu bionic/universe amd64 Packages

Can i somehow erase the 21.02.-modified version? WITHOUT the complete removal and new install (coz there will be an incredible amount of work to create all the scenes and FX again).

(Note: I'm a total noob, i use Ubuntu coz i'm too tired of Windows, and everything is cool but this little problem).