You have the Premium version which had a one-time payment ...right? Well it was announced that support for that app will stop here:
viewtopic.php?p=290636#p290636
and while you are at it also read this post containing the "why":
viewtopic.php?p=290748#p290748
I see there was a issue opened for blinds last week assuming that is what your issue is: https://github.com/domoticz/domoticz-android/issues/691
Add your finding/additions to it and I really advice you to remain professional as these "bitching posts" lead nowhere!
... oh and I see you were asking for an older version of the app, which really shouldn't be that hard to find.
