Did you set new tabs to use an empty page? If so, I think that might be the expected behavior ("in New Tab", i.e. the New Tab page, vs "in new tabs", i.e. any new tabs).
Bug 1718933 Comment 2 Edit History
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Did you set new tabs to use an empty page? If so, I think that might be the expected behavior ("in New Tab", i.e. the New Tab page, vs "in new tabs", i.e. any new tabs).
EDIT: if you're using about:blank for new tabs, this is a dupe of bug 1676492