I didn't realise it was something forum side - thanks for looking in to it!
Sadly it hasn't made any difference to me. I cleared all cookies / cache on my iPhone too.
If I go to kendama.co.uk then click the forum link, the window appears long enough for me to tick the 'don't show again' box, I then click 'skip'. From then on, if go via the main website or if I google search for the forum and click in directly, that same 'download/disable' screen pops up but too quickly for me to click 'don't show' again. It seems like the tapatalk page is loading before it gets the message to 'don't show'.
Anyway no big deal, so don't worry if it's work for you to sort out but if at any point you discover an easy solution I'd love to hear it!
Nice one:)