Also having the same issue - have to keep clearing cookies to get it to work.
The video ads on pages are also making it unusable on mobile now. O completely get why they are there but half of this message as I type is being hidden by an ad…..
About 3 minutes from opening to main menu - UK 150mb download speed, I can deal with that time.
Though I seem to be having luck compared with most people, started using yesterday and no issues so far!