You mean the R
BTFC11:
https://mikrotik.com/product/RBFTC11
?
By default it comes with an injector that is this one:
https://mikrotik.com/product/RBGPOE
That definitely uses mode B (4,5+/7,8-).
In theory a 802.3af/at compliant PD should accept both Mode A and mode B (it is the PSE that decides on which pins to apply power).
Your Cisco most probably uses mode A (1,2+/3,6-).
It is possible that either the thingy is not fully 802.3af/at compatible or that (for whatever reasons) it is defective and only powers from mode B.
You can try extracting the 48V from the Cisco and inject the voltage back in the RBGPOE connected to the RBFTC11, with something like this:
https://www.wirmax.net/en/alimentazione ... itter.html