Mac Mini M1 16GB unified memory (bought in 2021) Notice keeps popping up system has run out of application memory. Only running safari, slack, music, and messages. Less than 1.2 GB of memory.

Run EtreCheck Pro and post back here with your report.

to get EtreCheck directly from the developer, go to > https://etrecheck.com

for help posting the report, see > https://discussions.apple.com/docs/DOC-250000211

I also sleep my iMac and Mac Mini's 24-7, but tend not to leave RAM (memory) sucking App's open.

Most native macOS Apps are very good at taking and giving back to the system. Unlike some third party Apps that are good at taking, but then not giving back until you quit them.

Time Machine is Apple's Backup software.

see > https://support.apple.com/en-us/HT201250

That photoanalysis is a function of Photos that can take quite some time to finish, especially if you have a large Library.

You're welcome.

I see a few things in the report.

1) You use app's that require a lot of RAM (memory) and the M1 Mac's are not upgradable.

2) You need to restart more often (everyday or at least one a week) to free up memory.

3) You have no Time Machine backup.

4) There is/was a Photos task called photoanalysisd running in the background.

Things should pickup a little, once that tasks has completed.

The solution to 1) and 2) is to run less app's at the same time and restart more often.

The solution to 3) is to get an external drive to use for Time Machine.

The solution to 4) is to let it run until complete.

Yes EtreCheck Pro was developed by a well respected long time Apple Support Communities helper to make it easy to troubleshoot Mac's. It is a great tool and there is no personal information, serial #s, etc.. included in the report.

Sounds like maybe it is low free disk space, not memory?

see > https://support.apple.com/en-us/HT206996