If your single bay My Cloud is using v2.x firmware then it is Second Generation.
Your issues sound suspiciously like those people are getting after upgrading a second generation single bay My Cloud to the OS5 firmware. The main problem many face after updating the firmware to OS5 on a second gen is the OS5 indexing ties up the My Cloud to the point that it is unresponsive for many hours. If one is able to eventually access the My Cloud Dashboard, one of the suggested workaround is to disable Remote Access/Cloud Access and turn off the DLNA media server features.
If one is using OS5 v5.x firmware on their single bay My Cloud, see the dedicated OS5 subforum for the My Cloud where many are facing issues.
OS5 My Cloud
https://community.wd.com/c/os5/my-cloud-os5/257
