If it were Victoria she'd have the perfect strap for the particular lamp, at the specific time of day, and to coordinate with the paint, furnishings and accessories in the room. TTK would then be a bit jealous and get just a bit catty.
Something is effectively shortening the balance spring randomly.
What would be causing this?
The balance spring is sticking to itself because it is gummy from migrated lube.
What do you think needs changing now?