The reason is probably that your iPad isn’t compatible. Sadly it needs a newer version of hardware. The iOS version isn’t the limitation. It needs open gl 3
That’s a shame. Yes, both my iPads were too old to run Roon despite running everything else I use, so I had to get a new one. There’s no way around it for Roon and the platform they develop on sadly.
There’s a very good likelihood that the recently released API will eventually breath life into our older iPads with Roon, but toehat extent is unknown. It may be quite basic transport controls/volume etc.