I had an airline ticket to El Salvador. On checking in, a young agent for Copa Airlines noted that I only had 3 months left on my passport. El Salvador is one of those nations requiring a minimum of 6 months.
If an Airline puts me on the flight, they could be fined.
She refused me a boarding pass.
I tried 6 or 7 ways to get permission to get on that flight. All failed.
Finally a more senior employee of Copa suggested I try buying a last minute ticket on another airline. The other airline was happy to sell me an expensive ticket, ignoring the 6 month passport requirement.

My bad.
Still, I’ll avoid Copa airlines in future, if I possibly can.
related – A friend has a visa for Congo. But was not allowed on the flight because the visa would expire before she was scheduled to depart the nation.