When I rode outdoors, I had ‘snot problems’ in two points in the year. The first one was spring, when the rains come and the molds and fungus erupt after laying low over the winter, and two was in the fall, and it varied a bit making identifying what could be causing it.
Spring was very likely mold and fungus growth in the wooded areas and farmland I rode by. Snot rockets and goobers were a thing. The fall was generally pine, but also died detritus around. I do remember one year I could SEE the pollen pouring out of the pine trees, and the snot rockets were epic, and my eyes felt like they were rolled in dirt.
Now the interesting part: I tested negative for pine, pine pollen, mold, and mildew, in a scratch test. So, yeah, I’m making it up?
Over the counter stuff like Allegra, Claritin, Zyrtec, etc, seem to ‘titrate out’ and lose their effectiveness in many people, so I and tons of other sufferers do a ‘round robin’ swap of the available drugs, changing every month or so.
One other thing was, immediately pre-pandemic, I was having more issues, so someone came and checked the house. They found a black mold infestation due to some A/C work we had done. So we ended up having to have part of the house gutted and replaced. (that was NOT fun) and the problem has gone away.
Get tested, and get your HOUSE tested. Seriously. Our insurance covered most of the repairs so it made it a lot easier to do it. (We ended up having to replace out entire A/C system as it was packed with mold) Now more snot rockets, a ton less phlegm and goobers. Even ear blockage and sinus headaches disappeared.