My last few regens have only gone down to 25 or 30%, not all the way to 0 like they used to. Each time I was still driving for 50 to 100 miles after the regen stopped, constant speed on the highway. No error codes or anything like that. Each time its been in the mountains in CO, so a lot of up and down. Only thing I can think of is the downhill sections kicked it out of regen before it was done?