This issue with my 2003 Mazda Protege 5, manual transmission, has been going on for years. I’d like to sell the car, so I’d like to fix it.
On occasion I am unable to shift into first gear from a stopped position. This never happens in the late fall, winter, or early spring - it all seems to depend on how warm it is outside. It is always fine at the start of the trip, but becomes a problem in what seems like a period of time proportional to how warm it is outside. Again, when its cool outside, it pretty much doesn’t happen. But once we pass 25C / 77F it is common, and will almost certainly happen on any trip of over a 10 minutes. The hotter the weather, the faster it shows up as a problem.
If I leave the car and come back after it cools down, first gear works fine again. And I can downshift into first gear as I come to a stop with no issues - I just hate riding the clutch like that, so I’ve been starting in second gear instead.