For me I am still not able to log on to the online wallet with any browser.
When I use Chrome Incognito on my phone however, I am able to access the online wallet.
MyNXT support emailed me that they are still looking into it and that the difficult thing is that some users seem to have no problem at all, while others, like me, are not able to log on with any method.
I hope they'll be able to solve it soon.