I'm currently unable to set Allow Roaming on my modems. I've tested this on an LTAP mini and a SXT 4G. This with V007 of the modem firmware and RouterOS 6.45.1 or 6.44.3 or 6.43.16.
When I set this through the interface it shows the check mark but when I reboot it is gone. When I set this through the CLI: /interface lte edit lte1 allow-roaming
and set it there to yes, when I immediately reissue that command it's also back to no.
I'm unsure of a working workaround for this issue.