Great news. Seems @alfageme had provided some background on this in the issue:
We don’t currently support shared hosters since they’re quite painful to deal with. Your problem might be related to limited/shared access to a DB/permanent storage when using chunking. However, there’s a way to force the client to use the old algorithm and endpoint. Can you give a try switching the OWNCLOUD_CHUNKING_NG env.var. and restart the client? (i.e. launch the client with this variable set to 0 on cmd)
and the issue:
Something that changed sensibly from version 2.2.4 to 2.3.* is the use of the new chunking algorithm (#4019) if the server reports it - can you give a try switching the OWNCLOUD_CHUNKING_NG env.var and restart the client? (i.e. launch the client with this var. set to 0)
Its not the first time i had read about issues on shared hosters due to limited resources not able to handle the requirements of ownCloud. 
And i think especially the second text explains why this issue was showing up after an upgrade from 9 to 10. Probably only 10 reports this “new chunking” and thus the client had used it directly.