Reenabling alias server loses mail aliases (possible bug)

Hi, I have a domain in virtualmin with a couple of alias domain (the target domain is example.cz and aliases are example.com, example.sk and some other). There is a mailbox info@example.cz in the target domain and there is set up to copy aliases from target for all alias domains. I disabled (alias domain) example.com for few days. When I re-enable it, mail address info@example.com was not functional, until I switched the alias method to catchall and back again. Then the mail was functional again. Is it possible to be a bug?

Pletiplot