I have a M1 Mini and Macbook Pro M3. The Mini is my main design computer out in the shop and the Macbook is in the house which I use for some design work. I too have noticed that Lightburn is kind of slow to load and perform some operations. I also have a Windows 10 PC connected to a diode laser and it seems to load Lightburn significantly faster. I do, however have my files, art library and materials libraries stored on a NAS drive and figure that is the reason for the slowness loading.
Many have found connection problems with Mac and their laser to be an issue with how MacOS translates, or rather doesn’t translate the onboard USB 3+ to the USB 2.0 of the laser. The most common solution seems to be using a "dumb: USB 2.0 hub connected though a Lightning adapter. Faulty, cheap USB cables are another source of problem for Mac and PC users alike. I don’t think the cable is your issue since it works on other machines, but I would try a cheap hub.
The solution in this thread may also be an issue.