Same problem here. Tried the Citroen Update app first. Let the app install everyting. Then with a new USB stick. Without result. I also tried the obtain a 'new' license key by MITTNS. That gave the same error: Version not compatible with hardware..
Very strange because I updated my parents car (C3 2018) a couple of weeks ago through the Citroen Update app, and not a single problem! Didn't even connect the car with internet as described earlyer here.