My Mac mini 2018 (3 GHz Core i5) runs Mojave 10.14.6. The monitor is an LG UHD 27UK850.
After a 32 GB RAM update, the cursor freezes regularly but momentarily approximately every 4 seconds, a major nuisance with photo editing!
I use a wired mouse that is not Apple, but the same thing happens with a Magic Mouse 2 and a Logitech wireless mouse and another non-Apple mouse. Note that, apart from trying the Magic Mouse, I have Bluetooth disabled.
After trying several solutions, such as Safe Boot; reset NVPAM; By removing mouse-related list items in ~ / Library / Preferences, through the removal process, I discovered that 2 of the 3 USB-C hubs I use (USB-C to 3 x USB 3.0) seem to be causing the problem.
The centers that cause problems are not branded, but they have been working perfectly, and they do not cause any problems in a MacBook Pro 2017.
But on the Mac mini, even without peripheral devices connected to these hubs, the cursor freezes momentarily approx. every 4 seconds Remove the cubes and everything is fine.
The other hub, an Aerocool, caused Bluetooth interference on the MacBook Pro until I wrapped its lead in foil, but it still works well on the Mac mini and does not affect the cursor.
I am perplexed as to why more RAM seems to have created this problem, since previously my cursor never froze and the centers themselves do not cause problems on another Mac.