High power consumption on STM32L073-based board when running class B

[upwis-gabriel]

We have a custom board based on the Murata CMWX1ZZABZ_078, which is mostly identical to the B-L072Z-LRWAN1. I am trying to make a functional class B node based on the periodic-uplink-lpp sample with stop mode enabled. It seems to be working fine in class A, but when class B is enabled it almost immediately starts pulling around 10 mA on the 3.3V with peaks to 25 mA every second or so.
The strange thing is that I have seen it running in class B with a power consumption on the order of 100 µA, but either after some time or after a reset it will go back to being power hungry. Although, even when it was working "correctly" it still seemed to wake up the radio once every second.
Some of the testing I have done leads me to think that the power is not used by the TXCO or any external components.
Our network is EU868, our gateways are based on the SX1302 with a recent HAL package and packet forwarder and our network server is chirpstack. I am fairly sure that all settings are LoRaWAN default for EU868. The upload frequency does not seem to have any effect on this problem, but I have only used up to 5 minutes.
Has anyone else seen this kind of issue? We have had some issues with our gateways as well, so trying to figure out which end is actually causing the problem is somewhat difficult.

As an aside, I am running 4.4.7, i.e. LoRaWAN 1.0.3. I am having difficulties finding any information about the compatibility of the newer standard, not to mention 1.1. Should I just switch to 1.0.4, or could this have unforeseen consequences? If someone could point me in the right direction, that would be greatly appreciated.