I have the same issue here.
I created a new key using B4A 11.2 and when I put the app in play store, I needed to create another file key using the pepk.jar.
Now I have 3 keys: 1 to my old apps, 1 to the new apps to compile in B4A and 1 to publish the new apps in play store.
No problem to me, at the moment, because it worked, but I don't know what caused this.