Front wheel, drive train, does not get on the road

Have the following problem: wheel nuts in front left have solved, 2 lost, 1 torn off. Strong noise, guess first wheel bearing, wheel hung finally only loosely on 2 screws, rim holes oval…. Now car in front mounted, need in any case new hub since thread broken. Sample with mounted car (front wheels dismantled): Wheels turn at inserted gear but at speed 1500 rpm no further increase possible. No unusual noises (e.g. from wheel position) r) readable. As mentioned: At about 1500 u/min is the end. If I take out the gear also high speed possible. But if I press the clutch (without inserting the gear), again only low speed is possible, motor is not to bring about 1500 u/min. I don’t understand that. Why with gear or pressed coupling only about 1500 u/min?? If (in case of standing motor) a gear is inserted the drive shaft can be turned. Should the gear not be blocked? What is there? what could be broken, maybe it has something to do with ABS or slip control (if the car has such a thing at all)? By the way: Bjh 2021, 1,5 D, identical to Peugeot Expert, Citroen Spacetourer, Fiat Talento. Who can help?