Im on Unity 6.0 LTS with the latest URP version. I upgraded so that I could use post processing on render textures and still get transparent backgrounds. But not only does that not work, now I cant even get transparent backgrounds without post processing.
I have the same problem for a long time. So I did not find the only good solution of the laborer (I made a bad but effective method it cut the selected colors in the chamber in the shader texture as alpha clip).
So I will expect here with you on some solution because I am sure that it is.