It´s not a connection issue. When the EFB looses connection it gets a red triangle with a ! in the middle.
Hm this is a very strange bug…
I would uninstall everything, delete all Fenix folders, then deactivate the firewall and reinstall Fenix. Maybe this helps. But wow I have never seen such a bug. Sorry I don´t know what you could do.
But the good news is - you can fly IFR because the EFB is only needed for the V-speeds and nothing else.
You can input all data like Zero Fuel Weight, Center of gravity and more when reading the final loadsheet on the MCDU, and you can input the full MCDU METAR after checking the METAR mail from the departure and arrival airport.
The V-speeds wait let me think I have done this so often… the V-speeds are always the same when assumed you load the Fenix with maximum cargo, no passengers, and 4.5 or 5 tons of fuel.
It´s V1 135 knots, VR 141 knots, and V2 141 knots.
I have only flown a fully loaded Fenix once for flight dynamics and landing testing purposes (I don´t fly passenger planes but cargo or BBJ-bizjets only), I think with fully loaded tanks cargo section and passenger PAC count the V-speeds are V1 140 knots, VR 150 knots, and V2 155 knots (but I am not sure if I remember this correctly, I will have a look later what the V-speeds with a fully loaded Fenix are.)
I think you can even load the Fenix in the MCDU, PAC Cargo and Fuel can be loaded somewhere in the MCDU too (sorry for not knowing this exactly I have only tried this once manually loading several months ago in June after buying it, but I use the EFB to load it).
So you see you can use, program, load and fly the Fenix with almost zero issues without that EFB.
Only the V-speeds must be entered hmm let´s say with a little “creative freedom” because I don´t know how to calculate the V-speeds manually.
But the V-speeds are not really important, because I fly the Fenix very smooth and with slow and smooth elevator and aileron movement and because the acceleration is so fast, most of the time the nose comes up at 150 knots. No problem at all (or let´s say almost impossible for my fly like the V-speeds tell me).
But of course it is annoying to be unable to use the EFB because it is a feature the Fenix offers and it uses beautyfully animated features to calculate various stuff + a moving map inflight. This problem should be solvable somehow… I personally would start with a complete fresh installation with no Firewall, and go to the Fenix discord forum instead of trying to contact support a second time.