`bdt dev create` fails to create a Python 3.8 or 3.9 environment and installs Python 3.10 instead

I'm not sure where the problem is, but the following doesn't seem to work anymore:

$ cd bob.extension
$ #git checkout master; git pull  # just make sure you're up-to-date
$ bdt create -vv ext --python=3.8
...
$ conda activate ext
$ python -V
Python 3.10.6

I have the latest beta version of bdt installed (5.3.1b0-py39_6, arm/mac), as it seems.

Package planning shows Python 3.8 passing by, however it is later dropped for Python 3.10.

@flavio.tarsetti, @ydayer: Does anybody understand what is going on?