With the 'Delete Data on Quit' option enabled on Firefox mobile, this used to adequately clear (or seemed to) any state for Youtube.com. Some time over the las

With the 'Delete Data on Quit' option enabled on Firefox mobile, this used to adequately clear (or seemed to) any state for Youtube.com. Some time over the last few months this seems to have changed - I have to now go to Settings > Delete All Browsing Data (or similar) to effectively get Youtube.com to forget everything. Not sure what has changed there...