Sync problem between android and windows

[Hardhat]

windows 10; android galaxy S7a current versions on both as of 27jan 18; cloud sync methodology

sync works MAINLY.

However, there are a number of older tasks on my android that DO NOT show up on my PC after sync.

Thus, I am not confident that the sync is reliable.

Near as I can tell, all new tasks added to either PC or android seem to sync properly.

File struture also does not sync.  so tasks and folders show up on android that do not show up on PC.

Am unable to correct this unless i mannually delete each task. my concern here is that this implies that the sync process is not wholly trustable.

great program in general.  Seems that this is a "stupid" thing that sould not be happening.

Perhaps I have a corrupted file on my android?  (IIe been using the program since around 2013 I think so this could be it.)

Worst case: anyone know how i can "erase" all the tasks on my android without messing up the views?

Thanks for any thoughts.