Acronis nonstop backup works once, then fails to connect

MyCloud PR4100, Firmware 5.09.115, RAID 5, using Acronis TrueImage for Western Digital, MSI Stealth laptop running Windows 10.

I have the PR4100 connected to an ASUS AC1900 router, with a wired ethernet connection to my laptop.

I set up Acronis for non-stop backup so I can quickly backup and recover individual files when writing FPGAs or SW if needed.

The problem I have is that Acronis runs fine the first time, makes a full backup, then when I come back in the next day, after a period of time I get a Windows notification that says non-stop backup has stopped. If I open the Acronis app, it shows a broken connection (X) between source and destination, and when I try to manually enter the credentials, it says it cannot connect, but if I open Windows Explorer, I can go to the network and browse all the files on the PR4100 just fine.

If I power the PR4100 off and back on, it sometimes starts working again. Other times I had to restore factory settings in the PR4100 and start over. Also, sometimes the PR4100 configuration webpage will not respond unless I switch to another browser and log in, then it starts responding again.

I just now put my computer in sleep while I went to lunch and came back and got the stopped notification and a message in the Acronis window that says “Failed to lock the file”, and it won’t accept the credentials manually.

Basically, I cannot trust Acronis or the PR4100 as a backup if it keeps failing every day.

Any ideas on what I am doing wrong? Is this an Acronis issue, or a PR4100 issue? Should I switch to another backup program?