I'm experiencing frequent dropouts with iReal Pro on my iMac.
I.e. Playback stops (and audio crackles for a moment) and then restarts after a moment or two.
Sometimes it stops completely and I have to restart playback manually.

What are the types of things that might cause this behaviour?
It never used to happen.

My song list is just over 1900 songs at the moment.
Could that be the cause of it?
I add at least 1 new song nearly every day and I've noticed it getting worse and worse day by day.

My iMac has 24 GBs of RAM.
I'm on the latest version of MacOS.
My startup volume is an external 1TB SSD with more than 1/2 of its memory still free.
I'm using an original RME Babyface audio interface via USB.

[I just realized that I can turn off iCloud Sync.
I guess I'll try that and see if it helps.]

Any other tips or advice?