Yes, more than likely, a bad converter. You will probably want to assess the health of your battery at the time you replace the converter. Any auto parts store will load test the battery.
I have a Progressive Dynamics converter. It is 44 years old and still working fine. I have no other recommendation.
If you contact Best Converters and ask to speak to Randy, he will give you the model # and pricing on a converter replacement that won't involve replacing the distribution center.
Good luck with your 12V issues. I would replace that Magnetek sooner rather than later. It may be stressing things connected to 12 V.