Initially, I thought there was a random problem with my music (Roon music aok) but then discovered problem was restricted to the few low res files on my system.
Called in my IT guy. Switched NAS to SSDs and things got some better and then bumped RAM from 2 to 8Gb which improved things even more. Much quicker and more reliable and both changes also resulted in improved sound.
Cheers,
Dr. B
Had you given the NAS details and the tracks count we might have had some insight as to the lack of performance your system is constrained with. A low-end / spec NAS is seldom a good place to run an application like a Roon Core
Running the NAS on SSD is not going to help so much for the music storage BUT it is a necessity for the Roon Database location.