iMac intermittently freezes for 4-5 seconds

Hello everyone -

I have another "why is my computer freezing" question. I bought a new iMac last year, upgraded memory and ram as much as possible, and it's the fastest computer I've ever had. I was getting it just to do some light design work when my eyes started getting fatigued using my MacBook Pro. Turns out, this thing works better so I've ran Logic Pro, Premier, and other Adobe apps with no issues.

About a week or so ago, my computer will just freeze for about 4 seconds. Sometimes the spinning icon replaces the mouse icon. I have no idea what's going on. Everything is updated, there are no idle accessories plugged into it. I thought it was maybe a bluetooth issue (I'll notice it freezes because as I'm typing or moving the mouse, it won't move), but I plugged both the mouse and the keyboard to run it as wired, and it still does it. My Activity Monitor isn't showing anything take up too much CPU... even with the most graphic heavy tasks I still have about 40% idle. I could be on a website, in Pages, in Photoshop, or just clicking files on my desktop... There's no rhyme or reason. I even tried closing out every app and just moving the mouse around and opening file folders and it still freezes. When I type, the words will stop filling out what I'm typing but after a few seconds all the words that weren't typing will appear. It's almost like when your iPhone is getting too close to its storage being maxed out and the screen swipes in a glitchy way or when you text it isn't as smooth. I've turned off iCloud sync with my desktop, I've turned of Adobe Creative Suite... restarted it, turned it off... nothing works.

I've had computers that were about 10 years old start to act like this, but never anything this new. Anyone got any tips? I tried searching the message board but most topics were about Macs running slow in general or freezing and not coming back. Mine is running perfectly normal but just does these glitchy freezes that last about 4 to 5 seconds and it happens every minute or two. Very annoying.

Thanks for reading!