The weather station, as was installed, had 2 major flaws.
1. The Raspberry PI was too slow. Actually, the CPU would have been fast enough, but the GPIO polling was too slow, limiting the "read" wind speeds to 60Km/h.
2. The AQI (Air Quality Sensor) had an uninvited guest, obstructing the air intake. No air, no measurement.

So - to remediate, I replaced the current raspberry PI Zero WH with a PI Zero 2W which provides several times the speed of its predecessor. Instead of 1 CPU core, there are now 4, and the speed for each core is 1Ghz instead of 700Mhz. The WiFi is also way better than it was before.
For our uninvited guest, I had to put a "mosquito" net at the intake and the exhaust of the AQI unit.

Hopefully these issues will go away now.