Four Apple devices showing now position 150 miles away

Thank you for the additional clarification. Be aware that WiFi Only models of iPad lack GNSS/GPS capabilities - this function only being available to WiFi+Cellular models of iPad and iPhone models. If you are seeing issues with multiple GNSS-capable devices in the same area, the issue is likely to be external to your equipment.

GNSS and ISM radio systems may be unreliable is some circumstances, in particular due to jamming - which is becoming increasingly commonplace throughout mid/eastern Europe, the Mediterranean and Middle East. In addition to Russia and Israel employing jamming in support of their combat activities, many Friendly Nations periodically test their own regional denial of service capabilities - in particular in periods of heightened international tensions.

When using Broadband or Satellite internet systems (e.g. Starlink) or VPN services, the public IP Address of the internet gateway through which your internet traffic is routed may be in a completely different country/region to your actual location. Where your iPad/iPhone is using this location to infer its location, you may observe an incorrect derived location.

The prudent navigator will never rely upon a single source of navigation data - and will use all available navigation sources (multiple methods) to derive and confirm their location. 🙂

Setting aside the above, the general population have become accustomed to cheap and reliable navigation being available in the palm of our collective hands - often with accuracy to within a few metres of true. It is a sad fact that in this increasingly troubled world, technology is being deliberately subverted.

Jamming (denial of service) is bad enough, but modern subversion techniques often go further and intentionally "spoof" an incorrect location. Unless the error is of sufficient magnitude that the position error is glaringly obvious, navigation errors can go unnoticed.