I can confirm the save WebDAV problem on Android with Joplin version 1.0.271. I have two Windows laptops that sync properly with the same credentials on the same network. If I could roll back the latest app update, I would - but that doesn’t seem to be an option for Joplin on Android.
As already discussed in other topics, I’m sure Laurent will try to find a workaround. However, as also mentioned in other topics, at one point, there won’t be a workaround anymore. You can scream, you can be angry, it won’t change the fact that https will be the only protocol available in Google, Apple, Microsoft APIs.
So be happy that some apps still work somehow, sometimes, because they won’t for long.
Don’t think that I don’t understand your issue. I do, but developers can only use the tools and APIs they are given.
I think I will take a break on commenting on Android http sync issues. So long.