You have not mentioned what fails, what is slow, etc. so a bit hard to diagnose. But some LrC settings that can slow things down. These have nothing to do with OS version, but on a new computer, perhaps they got overlooked.
You have not mentioned what fails, what is slow, etc. so a bit hard to diagnose. But some LrC settings that can slow things down. These have nothing to do with OS version, but on a new computer, perhaps they got overlooked.