I've been getting this on my 2006 FEH - no regen braking when the OAT is 25-35F. It happens after a cold start even with it garaged for the night. Eventually after driving 4-8 miles the regen braking starts to function again...this is 2-3 times as long as needed to warm up the engine and get EV mode.

When it happens, the batteries still recharge from the engine or L transmission setting so I don't think it's due to fully-charged batteries or battery temperature. It looks like a lot of you out there don't see this so I wonder what's going on?