VHP GMT settings app no longer working

Just got my VHP GMT back from a Swatch Group battery replacement on warranty (battery died after a year)...now the GMT settings app doesn't have any effect on the target GMT time. I tried 3 phones...Pixel 5, Oneplus 7T, and iphone 12...all 3 send the flashes no problem, none of them have any effect.

I assume you'll all tell me what I already know...it's gotta go back again? Bit of a drag as it took 3 weeks just to replace the battery (sent to Toronto service center as Montreal doesn't work on this watch).

Cheers

Problem solved, it's called "reading the manual".

Carry on