Multiple networks login

When some of my users are logging in by rublon, they complain about that rublon obviously takes only one IP address as trusted. Once they try to login from another network with different IP address, they are forced through the verification process every time.
Logging in from multiple IPs is not so unusual these days – I think a lot of people do that. But verification again and again is no fun at all.
How can this be solved?
Are we doing anything wrong?

https://ww.wp.xz.cn/plugins/rublon/