Migration from Exchange 2010 to 365 very slow

Hello

I have extremely slow problems during this migration, I applied the policies required to the source:
New-ThrottlingPolicy UCCSPolicy
Set-ThrottlingPolicy UCCSPolicy  -EWSPercentTimeInAD $null -EWSPercentTimeInCAS $null -EWSPercentTimeInMailboxRPC $null
Set-Mailbox <ServiceAccountName> -ThrottlingPolicy UCCSPolicy

But the problem persist.

 EWS throttling in Office 365, disabled.

Problem persist.

the time is 2.5 days for an 8G mailbox,

during previous migrations it was 4 hours maximum

there are no bandwidth problems, there are no network problems, there seems to be a "block" in exchange 2010
can someone give me some advice?
Thanks