Can't register SC6000M's

Wasn’t sure where to post this, so if this is the wrong section sorry. I’ve tried registering my SC6000M’s but every time I enter the serial number the website tells me it’s invalid. I’ve tried with the (21) prefix and without it. I was able to register my X1850 just fine (without using the (21) prefix).

Noted. I’ll inform staff. Cannot add mine as well (non-M).

Update Registered at least my non-M’s.