Problem Lambdaprobe heating / Euro2

I just can't get rid of the eternal problem with the Lambda with my V8, which haunts me like a curse.
After the thread on the X-pipe is crumbled 2 times during the construction of the Lambda, I just can't get the current Lambda to run 100%.

In fact, he had pulsed strongly and fluctuated in consumption. Test Lambda off -> it's okay.
After that Lambda new, he also runs better, the fluctuations in the consumption indicator are gone, but he pulsates sometimes, especially when he is cold and after passages with engine brake quite extreme.
Lambda cable off -> it's okay.

Since it's so sporadic, I guess lambda probe heater. Relays switched. Backup checked -> Errors still present.

I just looked at the SLP of Lambda (01.7) in the rep. So far I was of the opinion that the 3 connections of the Lambda are 1x signal and 2x heating, mass over X tube.
But when I look at the SLP, it looks quite different to me as a layman. Actually, it should not matter how the Unifit probe is occupied on the 2 white cables. After the SLP, however, this is not the case at all. Do I see that right? Can this be the mistake ?

I want to register for the TÜV next week for Euro2 and chassis, since the Lambda will probably make a dash of my bill, right?

Thank you for any helpful note ;)