RT-AX88U & NAS (WD MyBookLive) not accessible or horrible performance when browsing mounted drive on nvidia shield

[Shaitan00]

Everything was working great using my linksys EA4500 (WIFI) for my nvidia shield (media player) which has KODI loaded to play files off my NAS (WD MyBookLive); on the shield I mount the NAS drive so KODI can browse it (fantastic and stable for 5 years). Then last week I purchased the RT-AX99U (for much needed WIFI improvements around the house) and now every few days the nvidia shield is unable to access the mounted drive, or the NAS itself - it falls to a crawl (taking 60-90 seconds to change folders and often simply crashing) - the only fix is to REBOOT both the shield and the RT-AX99U router (multiple times) and eventually they seem to "sync-up" and it works for a few days?

This is getting really annoying - and honestly I have no clue if the issue is compatibility; the share; or something else?
Any clues?

 

[dosborne]

it falls to a crawl (taking 60-90 seconds to change folders and often simply crashing) -

Are you able to run diagnostics on the WD units and the drives (or access system logs)? Can you try your old setup to help determine if the issue is indeed related to the new router or if it is simply a failing nas/HDD?