Monzo plus and cornerstone

So I signed up to cornerstone the other day through Monzo plus and came across something a bit annoying. You have to go through the built in browser in the Monzo app but when you go to complete the purchase you get redirected to the 3D secure thing that takes you out of the browser to approve then you cannot get back into the browser to finish the purchase. A bit annoying as I tried twice then just used the text feature in the 3D to complete.
Just an FYI really wouldn’t call it a bug but should be sorted.