iMovie on Mac Studio issues

Hey guys, I recently bought the Mac studio: m1 max, 64gb ram, & 4tb flash drive. The rest of the specs are stock. I am a content creator. So I brought some old projects over from my old iMac via external hard drive. I did not do any integration. The issues I am having is lagging and extreme slowness. I have experienced this with1080 GoPro footage and also 4k drone footage. The only thing that stands out is, it happens when I do my initial editing, when the project is at its longest ranging from 1 hr to 1hr and a half. All my videos wind up under 30 mins when the edit is completed, most around 15 min mark. The only other thing I noticed was it happened also when I overlayed footage over a clip.

This was a big investment and my lively hood and it slows down my work flow down a lot, takes me longer to do everything because of the lag. I went threw my library and manually deleted some old projects that I probably won't use. So iMovie doesn't haven't to preload so many projects all at once. The whole point in getting the studio was for me to be able to dig back in old footage when need be. I never know when I made need to use something that I have already shot.

I am currently using the newest edition of iMovie. I don't see how I can be the only one experiencing these issues with this brand new machine. From everything I understand the Studio shouldn't be struggling at all especially because I haven't pushed it near its limits.

I bought the new studio to get away from all these problems that I experienced on my old outdated iMac from 2014. Please any help would be greatly appreciated. Thank you for your time and understanding.