@Junior: We have not been able to reproduce your issues. Further details are included in the support-ticket you posted.
New update deletes thumb nail pic from all release music under the release tab. Also I can't delete pic from AIFF file with more than one pic
Please retry, it should be available now. (Just tested)
... download is unavailable.
Alan.
Mikael Stalvik
https://implodedsoftware.wordpress.com/2020/07/05/helium-14-7-1-now-available/