yep RCA
gunk in the regulators seems to be a common problem related to this.
as part of the pm on a truck it is recommended to drain the regulator to keep this from happening.
LP gas tends to have certain additives that cause this in today's LP gas market, most of the time just simply changing the LP supplier solves this problem but that is a whole different discussion that has already been brought up many times here in other posts.

glad you got it worked out