Support including Chrome Type in web parts migration in pages.
Migrated Web parts from SP13 to SPOnline don't include the chrome type attribute as it is and set to "Default".
So, if I have a web part that its Chrome type is set to "None", it's set online as "Default" instead.
Long Cheng commented
Could you please elaborate more on this issue? We could not reproduce this in the lab? Could you please explain more which Web Part you are using?