When you turn on debug logging (just for a few moments) while copying with Teracopy, does the log file contain any messages with FILE_NO_INTERMEDIATE_BUFFERING?
Another test: If you downgrade to Cryptomator 1.4.11, is it faster?
Yes, TeraCopy’s slowdown with Google Drive File Stream is a known issue, often due to verification overhead or compatibility.
For alternatives that auto-resolve errors and conflicts, try GS RichCopy 360 or GoodSync, they’re ideal solutions in 2026 for faster, reliable transfers.