@juststarted hey, sorry for not replying (I didn’t check discourse in a while).
In the meantime (PyMC v5.7.0) there was a bugfix that should apply to at least one of the problems you described.
If you run into other problems, please open an Issue in GitHub - pymc-devs/mcbackend: A backend for storing MCMC draws. and tag me, then I won’t overlook it 