Hello and Welcome -
My name is ***** ***** Im happy to help / advise.
Certainly that would be the next step forward yes - disconenct the batt terminals - but note - have the keys out of the car ... Then - use a wire and connect the pos and neg battery "connectors" together - ( not the battery terminals ).. and leave like that for one hour.. then undo them and replace on to the battery.
This will properly drain / reset / reboot the systems.
If that works, thats great.. If not.. ( and you should do this really anyway )... check the condition of the battery - you really need a pro test doing on it - to ensure it is actually holding a full charge. A faulty battery will appear ok - but faulty cells can cause this / what you have.
Check the cables etc too - inc the connections on the pos circuits - and the main grounds..
One way or the other should sort this -and at the same time, the shift lock.
Let me know how you go..and / or let me know if you need anything further on this..
~>>~~>>~ Meanwhile now - Please do click on the "Exc / Ok rating" for me at this time.. "Thank you" in advance for that .
.. Note that you can get back to me anytime at all after doing the rating - it doesn't close you out --
Best Rgds, MIKE.