How do I resolve sound delay issue in Logic using a new Mac mini?

I recently purchased a new Mac mini M4 Pro in order to replace my 2014 iMac. I specifically wanted to use the new Mac solely for Logic, however, when playing a guitar into a track, there is a noticeable delay which makes the system completely unusable. I've read about and tried all of the recommended fixes, like Low Latency Mode and adjusting the buffer size etc, but nothing seems to fix the problem.

My old iMac works perfectly with Logic and there is no delay when playing guitar into a track. I've compared all of the relevant settings in both Macs and made sure that the are identical, but the problem persists with the new M4.

I'm really at my wit's end at the moment and I'm regretting buying the new Mac. Hopefully, a knowledgeable person in this Community will be able to put me out of my misery.

I should mention that, at the same time as purchasing the new Mac, I also purchased a new Focusrite Scarlett Solo interface. However, before anyone blames the new interface for my problem, I've tried it with both Macs and the problem only persists with the new one.

I do hope that someone can throw some light on my dilemma. As most of you have probably already experienced, Apple are not helpful.

[Re-Titled by Moderator]