But it doesn't say UCI. It's on the side of the TRV info so it's not in the main part of all the information like name, passport number, issue date, etc. They're on the side. Both start with Bs. One has 9 numbers the other has 8....
I don't know if I'd get anywhere trying to call the embassy and asking them to give the UCI number from a previous TRV?
If that visa was for a visit you may not have a UCI. If you ever had one that never changes! It remains the same. Mine was always appeared on my work permit. TRV issued for visit may not have a UCI attached to them. (I thought you are a worker in Canada)