Version of OpenTTD

Nightly 20210226-master-gaf326753a9

Expected result

This is the result of dragging a vehicle from a NewGRF providing articulated vehicles in 1.11 beta 1:

Actual result

This is the result in a recent nightly:

The articulated units split apart and become misaligned. This is an extreme case (Timberwolf's Trains has each vehicle composed of 3 articulated units, so the screenshot is actually a 6-unit articulated vehicle) but can be observed in any GRF which provides articulated vehicles, either road or rail.

This does not affect non-articulated vehicles, or vehicles using the built-in "double-headed" logic. It may only affect vehicles shorter than 8/8, I was unable to assemble enough GRFs to test this theory.

I also noted in this version that the vehicles do not align with the "sell vehicle" and other buttons, this may be related.

Steps to reproduce

Install a NewGRF providing articulated vehicles (tested: Timberwolf's Trains, Timberwolf's UK Road Vehicles 3, Bob's Random British Vehicles).
Build an articulated vehicle in depot.
Drag the vehicle.