Question about Xiaomi 5G CPE Pro

My data consumption with the Xiaomi 5G CPE Pro is 5 times higher than before. Previously approx. 200 - 300 GB per month, now 1500 - 2000 GB. Even at night about 20 GB are consumed (most devices off or standby). Does anyone have any idea what is consuming so much data? I have changed the access PW. I would rule out an external consumer.