Appearance of "sst_tmp" files, inability to delete them or prevent their creation

[Adrien66]

Hello, when I transfer my files, sst_tpm files appear after an error has been detected during the destination search. In this error, the destination has a different name to the source, which is not normal. I've searched the relevant threads but I can't seem to find a viable explanation.

Can you please help me?

Here is the link to the screenshot of the error alert: