[PXIe] fix issues reported on SPEXI7U V2
The following issues reported on SPEXI7U V2 also exist on the PXIe WREN:
https://gitlab.cern.ch/be-cem-edl/fec/hardware-modules/spexi7u/-/issues/85
https://gitlab.cern.ch/be-cem-edl/fec/hardware-modules/spexi7u/-/issues/86
https://gitlab.cern.ch/be-cem-edl/fec/hardware-modules/spexi7u/-/issues/87