Compton doesn't run at startup

Support & Help Requests
#1

I have installed Compton and enabled it through Mate Tweak. I expected since there is integration that it would now just work at startup, though that isn't the case. I also tried adding Compton to Startup Applications, though that has still had no effect. Running Compton from the terminal after a reboot returns the following:

vsync_opengl_swc_init(): I'm afraid glXSwapIntervalSGI wouldn't help if you are not using GLX backend. You could try, nonetheless. Another composite manager is already running

I realise its no longer officially supported, but I would appreciate any input anyway.
Thanks folks.

#2

This is no longer after I purged every thing compton related:
sudo apt purge compton

Rebooted, the installed compton again:
sudo apt install compton

Rebooted, and Compton runs fine.

If a mod could point out to me how to mark a post as solved, that would be great.

#3

At the bottom of the post that solves the question, there are three dots - click on them and the opportunity to mark as solved is displayed. Click on the green box containing a checkmark and the entire post is marked as solved.

Edit: I'll do it.

#4

No idea how I missed that. Thank you very much.