ADV7189B to ADV7179 genlock problem

Dear Sirs,

prior to develop a special circuit, I'm trying to connect, back to back, one ADV7189B to a ADV7179. I do have problems to genlock the subcarrier. It's a PAL B application. With Extended Output Control (Bit1) = 1 on ADV7189 and MR22=1, MR21=1 on ADV7179, the ADV7179 subcarrier (burst) seems to be in free run mode. With MR22=0 and MR21=1, burst is jumping alternately +-180 Degrees. SFL pin in ADV7189 decoder is connected to SCRESET/RTC pin in ADV7179 encoder.
Any Suggestion?