Hopefully someone else will chime in with more suggestions. Have you sent a PM to one of the Dish reps here (names in green)? Matt G, Mike H & Tommy F all have been helpful when I needed something. Seems like you've tried all the usual things, they might have another idea to get things working for you.
I notice DA is not listing all timers( more then half of my timers are missing when view threw DA), and when deleting recordings they disappear and re appear with in seconds, I can log out and log back in 2 hours later and see the recording I deleted are there again, I will delete them and watch them reappear again with in seconds. I windup have to delete the same records over and over and over till the stick, it some time bug out when there multiple records to show, say 5 recordings, and if delete them all it might start show record from other shows in folder of recordings that was deleted.
Creating timers or editing timers threw DA is missing functions namely "folder" option you cant set that online and ANY timer you edit that had "folder" set will revert to having no folder.
I had timers where DVR listing wouldn't even populate but timer and schedule did. I had times where it say box is OFFLINE but and had no DVR recordings listed yet I could stream live tv just fine, despite it say the box was offline.
There is no option to see what is trash folder, let alone delete or restore from it online, but i can see how that could be security issue and there for there no option to see that online
DA while works is rather buggy and leave alot to be desired.
You might try from another location. Set up your device WIFI using the router at a friend or relatives house and see if it works using their network (first verify their download speed is over ~4Mb). Determine if problem is with router/network to/from device or not.
Until you determine the source of the problem the fix will be tough to find.