NAS DNS alias change not taken in account by Cobian

[fledorze]

Hello.
We are migrating to from a old small NAS (QNAP) to a bigger and newer one (SYNOLOGY).
Our initial plan was to just change DNS alias nas.site.local => qnap.site.local TO nas.site.local => syno.site.local. in the FTP task.
But even if nslookup on host gives the good answer (syno.site.local), Cobian continue to synchronize to old NAS, even after service restart.
I reconfigured Cobian with syno.site.local directly => working good
I reconfigured back Cobian with alias nas.site.local =>The file are synchonized to old NAS.

Has Cobian an internal DNS cache sthat I should clear ?
Thx

[cobian]

No. It doesn't caches the DNSS at all.