>> Has anybody got any idea why the Asiair should keep disconnecting.?
I can think of at least two possibilities. (1) Inadequate power supply capacity, and (2) poor WiFi signals.
With the original ASIAIR, try to use either the original 12V-5V converter, or find a power supply that is able to source 3A at 5V. Use a short and heavy gauge USB-A to micro-USB cables (e.g., find cables that are specified for heavy duty phone charging).
If you had swapped the original plastic case of the ASIAIR for a metal case, swap it back. Or find a plastic one at Amazon.
Try mounting the ASIAIR so that it does not move when the telescope changes position -- if the signal quality is already marginal, the directivity of the WiFi signals as the ASIAIR is moved may be enough to cause a null in the signal between the ASIAIR and its WiFi client (home router in STN mode or as access point to the tablet). That could cause loss of connection to the ASIAIR.
You can use a WiFi probe (many available on Android) to check WiFi signal while you slew the mount around.
If WiFi signal quality is a problem, try attaching the ASIAIR using ethernet to a travel router that is configured as a WiFi extender to the home network. Then access the ASIAIR from the home network. But, remember that signal quality is more important than signal strength. Multipath can ruin a WiFi signal even when it is strong.
My own configuration consists of an original ASIAIR mounted on one leg of the tripod, with a TP-Link travel router also mounted to the leg of the tripod. An ethernet cable connects the ASIAIR to the travel router.
You can configure an old unused router for such a purpose -- many of them (especially Netgear) can take 12V power. Non-travel extenders don't work as well for such a purpose since they are plugged directly into a wall outlet of the house, and you still depend on a WiFi signal from the ASIAIR to reach the extender. With a travel router next to the ASIAIR, you do not use the WiFi signal from the ASIAIR at all, although it is still visible if you are close enough.
Now that ASIAIR supports direct connection, the most reliable and highest speed way is to connect the ASIAIR with a long run of Ethernet cable to your home router (or a extender or mesh beacon).
Clear skies,
Chen