I found #883554 when googling "implicitclass cups". That's a difference between the two print queues:
One is
ipps://Kyocera%20ECOSYS%20M5526cdw._ipps._tcp.local/ (works)
and the other is
implicitclass://Kyocera_ECOSYS_M5526cdw/ (the not printing but connecting one, btw never created or configured manually).