Murano Hybrid Transmission Limp Mode

I've seen similar problems, though not specifically on a Murano hybrid. Slipping and weird shifts could be a number of things. Have you had any fault codes appear? I once had a torque converter issue that presented similarly. It might also be worth checking the control module.

Do you know if diagnostic trouble in the traction control system might cause this as well?

That is indeed possible. I would suggest taking your car to a trusted workshop. It's hard to say, without a professional diagnosis, if the symptoms are related to traction control, torque converter issues, or something else entirely.

After taking it to a specialist, they confirmed it was consequential and covered under warranty; 0€ repair cost.