Running OSX, Wine, HeidiSQL V9.4.0.5125 (32 bit), Docker, MariaDB.
Attempting to close the tab gives me a message in the log of :
/* Cannot close tab with running query. Please wait until query has finished. */
Which is sort of rubbish as I've restarted the mariaDB container.
Even closing all the hosts leaves the tab open and still cannot close the tab.
Only option is to force kill Wine.