Regeneration help

Hello i am posting for a friend he has a 2010 freightliner cascadia with the dd15 has about 500k miles on it also has a isx engine. Me and help work the same job he is recently complaining about doing regen often i usually do 2 regen each week maybe 3 max when the weather is hot or work is busy. I have a 2011 cascadia dd15. We dont idle as much and are very local so 50 miles max a week so no possible way to do passive Regen on highway since we dont run highway ling enough. So we always do park regen. He recently been complaining that he has to do it almost everyday and it last about 13 mins or so. He sent the dpf filter for a cleaning. Yesterday he showed me the light which goes on his truck which is not the regen light its the hot exhaust light. He thought that was the regen light his dash and mine dash look different but i always get regen light then while doing regeneration the hot exhaust light goes on. But all i see on his truck while he is doing his regen is the hot exhaust light? Is that normal i am thinking he has a fail sensor somewhere its a new truck for him and not familiar with regen. I am thinking he has a fail sensor and each time he is driving he gets the hot exhaust light and he thinks he has to do park regen. Thats why i think his regen are so short. He spent $1500 just to clean the dpf filter and the problem is still there. Too much regening. Below is the light he gets not the normal regen light while driving.

 

Another thing is i dont know if he is just seeing the hest light and is thinking its the regen light and then doing a park regen. But also why would that light come on and not the regen light. Either way i told him next time just wait it out and let it stay on for a while to see if he gets another light. Still sucks in the end spending $1500 on something that didnt need to be clean. I am still learning about this emission crap and my fellow o/o have the same trucks as me so knowledge is power. But i guess taking it to the right place is key.