Not all sfp GPON modules are the same.
Most sfp GPON modules will only work in a device that understands GPON.
There are some sfp GPON modules which have the GPON electronics/firmware included in the module so that they can function in most sfp devices and then participate in a GPON fiber network.
EDIT - I installed and tested one or two dozen Mikrotik GPON modules ( inserted them in outdoor cases containing the Mikrotik router ). All of them worked until the 1st warm summer day then all of them bricked. I have one remaining Mikrotik GPON module that still works after all of these years - it was installed in an airconditioned Lab where we pre-tested prior to installation.
The Mikrotik GPON modules ran
HOT and without any fan cooling from an air conditioned room, the temp would skyrocket to a temp so hot that they would turn into a brick and can't be recovered.
There is a chance that your Mikrotik GPON module may of already been cooked and is now a brick - and that might be why your Mikrotik does not recognize it.