Not just an iPad, I cannot access PPRuNe from my usual browser on a PC, either. To be able to post this I've had to fire up an old Windows 7 PC, connect using a VPN and that's enabled me to try and see what's going on.
The problem seems to be with something called Trustarc. It's not completing a script, so hangs with some sort of GPDR compliance window, just displaying the "loading" thing. My limited looking around seems to show that it's definitely the Trustarc thing that's causing the site to just lock up. I've tried clearing cookies, restarting the browser, all the usual stuff, but the only way I've been able to get in to post this is by firing up an old, and fairly insecure, Win 7 machine, that's running Palemoon as the browser. Even then I have had to "allow everything" to get this to work.
The Trustarc script hang is before the lists show, so there is no way to access anything at all. The whole site is greyed out behind the Trustarc pop-up, with no way that I can find to clear it.