Synchronize doesn't work with smartphone

[markvp]

When I select a folder on my laptop and a folder on my OnePlus 13 smartphone, and try to synchronize them, I get the message "Operation not supported for chosen folders". It works fine if I do the same with a folder on an external harddisk.
I think synchronizing should be possible because I can copy files manually to my OnePlus 13.

FreeCommander XE 2025 Build 921 32-bit public - Windows 11 Pro 24H2