Oh damn, my bad!!
I forgot that I had commented out the "compatible" tag in my packager script for my classic addons (as you told me here:
https://www.wowinterface.com/forums/...220#post336220). Guess I should make this such that it is at least applied for my retail addons.
(The curl instruction I posted above was a dump created by my script, in which I did not comment out the "compatibile" tag...)
Regarding the duplicate changelog: Let's see if it comes up again...
Sorry for the fuss and thank you so much for your support!