I am traveling VIE-LHR-LAX and back later this year and want to clarify some things. I am a Salvadoran national (SLV) living in Austria with a valid residence permit. If I input this into the UK Home Office visa check website it results that normally I would need a visa to transit though the UK, but I qualify under 2 exceptions (EEA common format residence permit and valid US visa) for transit without visa (see image).
I understand airlines usually use timatic for document checks at check-in, so I checked this same itinerary with a free Timaticweb2 trial and got that I need a transit visa for the UK and the exceptions are not listed (see 2nd image). BTW, the free IATA travel centre resource shows the correct data according to the UK Home Office website (see third image).
So my questions are:
Why the discrepancy?
Will the airline here in Austria not allow me to board due to incomplete timatic results?
Can I contact UK Border Force via email (I can't find an address though) and will they be willing to clarify?
Edit: Including the document input below (note that those dates are fictitious lol)