Error copying messages from subfolder using davmail 4.5.1

[retorquere]

I'm trying to move messages from Exchange to GMail; it works for non-nested folders, but for subfolders I get

[23:53:34] [debug] [>] updating mailboxes
[23:53:35] [fatal] mailbox not found: Archive/AAA

which indicates it correctly identifies the subfolder but then apparently can't reach it. The folder itself is reachable -- the command below (using impasync) works:

/usr/bin/imapsync --host1 localhost --port1 1143 --user1 USER1 --passfile1 PASS1 --authmech1 LOGIN --sep1 / --prefix1 Archive --host2 imap.gmail.com --port2 993 --user2 USER2 --passfile2 PASS2 -ssl2 --authmech2 LOGIN --prefix2 @HAN --include "Archive" --delete