When I was mid-career, frequently I would shave with a disposable and water, no soap at all. The shaves weren't that good, but I wasn't in any way irritated in spite of no soap.

So as a diagnostic tool, I'd recommend a disposable and water, and if you don't get irritation, try phasing in shaving soap, nothing else, if no irritation, follow with AS on the next shave etc.

I too would suspect a fragrance or soap constituent. Mike's Hungarian Lavender shaving soap lights me up like a flame and I'm typically not that sensitive. But with HL I might as wrll burn the hair off with a Bernz-O-Matic.

Cheers, Steve