[Solved] VW T5 1.9TDi (2006, 75kW, 420,000km) - Missing Gears 1, 3, 5: Possible Slider Issue & Clutch Tips

I bought an occasionally damaged Vw T5 from the company I work for, year 2006, 1.9 75kW engine, Long 9-seater, mileage 420,000 km. There were various problems with the car before, at the moment the gearbox broke while traveling from Ukraine. There are no 1.3 and 5 gears, you can go to 2 and 4. Has anyone had such a case? Apparently it has already been repaired with us, like a plastic element, a slider or something, apparently it is available without removing the crate, through some cover. Can anyone show me what to look for? On the other hand, I will probably have to remove the gearbox because the clutch has hit my head strongly during this journey, but I want to leave it at the end, after repairing the gears (if it can be done without removing the gearbox) and after road tests. If anyone did something similar, please give me some tips

at the gearbox there are such plastic connectors very often they are the culprit of what you write about - the purchase and replacement costs are small

Added after 8 [minutes]:

ask someone to move the gearshift lever first from left to right then up down (e.g. 3-4). At this time, watch what happens next to the gear selector and you will know what happened.

Thank you for the suggestion, today I found a moment to look into it, you were right - the plastic "paw" of the selector has a hole, probably a square, back puts gears in the front and you can only put the slack in the front. After Christmas, I will take this paw out and try to add some metal hole, maybe it will last longer

I will add a further part, it turned out that the selector's "paw" at the gearbox is, however, steel and the spline is in excellent condition, the spline on the selector shaft in the gearbox is worn.

I am closing the topic, the selector in the chest was to be replaced (only available on the website, as a complete one - the roller cannot be bought alone) and the selector's paw. For this all bearings in the gearbox, the car is driving nice