Reverse light has constant power

I replaced the tail/ reverse lights with the new combination LED lights.

Two nights ago I noticed two of the white (reverse) LED bulbs were lit on the right hand unit. This unit was being replaced under warranty, so I just snipped the wire.

Last night I noticed the left unit was fully lit, so again I snipped the wire for the back up lights.

Today I did some troubleshooting and found there is 9 volts DC constantly feeding to the reverse lights.

The truck is off and in park.

I thought I would try to trouble shoot before I start tearing into the wiring harness.

Any troubleshooting tips would be beneficial.

Thanks for your time and responses in advance.

John