Yes pretty sure they moved to Internal Convention Center like the pp office did. So there you find the MOFA office for the government stamp of authentication.
Not at your consulate
He said he needs a stamp from a Thai government office which his consulate is not.
Foreign consulates don’t generally authenticate documents of other countries.
Use to be a place in the provincial offices that did certified translations of routine Thai documents. Don’t know if they moved like the PP office did.