[Bug]

[Turusore08]

Connection Error: Connection attempt failed.

[BertLindeman]

This error has been reported a few times before.

#1355
#2128
#1889

Some of the discussion might give some ideas of what to try.

Usually the best way to solve these kinds of issues is to use Wireshark to log Bluetooth packets to see what is going on at a low level (instructions).