Version: M51
OS: Android

What steps will reproduce the problem?
(1) Enable reader mode. Set to "Always" would be easier.
(2) Visit any website, and wait for the Reader Mode infobar to show up.
(3) Change orientation.

What is the expected output?
The Reader Mode infobar should be there.

What do you see instead?
The infobar is gone. Refreshing the page would bring it back.