Already posted this to the Tasker subreddit, but seemed worth bringing up here too so I'll just copy what I said there: edit: So after doing some troubleshooting on my own I've determined that Pushover has the same issue, so it isn't necessarily AutoRemote specifically being at fault here. Still would appreciate any help I could get in getting it to work properly. I did notice that there was another app, "Google Services Framework" separate from the "Google Play Services" that was not whitelisted by default in the battery optimization menu, so I went ahead and whitelisted that one too, I'll test if this has made a difference after my phone has been sitting long enough to be sure. edit 2: It seems like there may be a combination of factors at play here. After whitelisting Google Services Framework and enabling Push Notifications Fixer again (whitelisting Google Services Framework by itself was not enough to fix it), it seems like it may be fixed, but I'll have to do some further testing after letting it sit longer to truly be sure. edit 3: Nope, thought I had it but after leaving my phone sleeping for several hours it once again failed to catch the notification.
sorry, Samsung is known for over "optimizing" stuff which makes stuff like this happen from time to time I really have no way of fixing it unfortunately besides the stuff you already tried with the push notifications fixer
Yeah, I turned up a lot of stories of people with similar problems with Samsung phones so eventually just gave up and switched over to my tablet for anything that needs to run in the background and accept push notifications like that. Has been working well enough over there.