Laser is moving too fast on new pc but works fine on old PC

Originally I had grbl on a uno with a cnc shield and used it on my old garage computer well. recently I decided to upgrade to espduino32 so has 32bit support. also, I updated my computer to a thin client with an SSD. The problem is after the new computer it seems my laser is moving too fast before 1200mm at 40 would burn fine but now to get this result i have to set the setting to 50mm to match the speeds before. i tried on two different computer and still the same but I tried it on my old pc which works great. the machine settings are the same. is this a lightburn setting issue or is it my firmware?