Centurion USN1202 Problems

I just bought my first house a few months ago in the Central Florida area. Comes with a totally beautiful in-ground pool/spa. Its also a very complex system which I am still learning how to use and control fully.

I noticed the other day that when the spa filter gets turned on sometimes it will work fine and other times it will not. When its working fine I can see the water swirl under the clear plastic filter cover in the pump area. When its not working, it sounds like it is, but the water is not swirling and its definitely 100% not pumping.

So, sometimes the pump works and sometimes it does not. When it works and when it does not, the pump sounds basically the same.
I read about changing the capacitor if it makes a humming sound. I am not really sure if this is considered humming or not, its pretty loud... I went ahead and ordered a capacitor anyway because it6 cant hurt to try that cheap fix.
I was hoping someone on this forum may be able to put me a bit at ease by telling me what they think it can be, based on my description?

The pump is a 2HP Century Centurion USN1202