Yea, gotta be something odd with your setup.

Currently I have one phone (of several) thats syncing en excess of 10,000 files, some only on Wifi (with 3 access points), some wifi/cell data.

ST knows the state of a file, so a disconnect should have no effect. If you’re getting corrupted files, I wonder if something else is going on which may also affect another sync tool.

Try Resilio for the same folders, see if you have the se problem (disable aybthing of course, otherwise conflicting edits will cause file corruption).