OpenBazaar + Whonix is not well documented.
A workaround might be to increase max control port connections as described here for Whonix 13. Whonix 14 increases limit from 5 to 50.
BUT if OpenBazaar is flooding control port with requests, it would be good to know why. Perhaps, Whonix is filtering the requests and causing OpenBazaar to repeatedly send the same request.