Can you clarify this? Isn’t 3.13 newer than 3.6? Can you give more specifics about what precisely is failing? From your message I can’t tell if this is a PyMC issue or a spyder issue.
You can use Python 3.11, 3.12, or 3.13 with PyMC, if falling back to an older python version would be helpful. 3.10 is no longer supported by the scientific stack, according to the numpy depreciation schedule, and 3.11 support will end in September.