Not only similar, they are identical.
Both the chips are 1.8 x 1.8 mm in size, the vias pattern and design is identical. The surface finish of these chips is also identical.
Very interesting: the LMP W5050SQ3 (and FFL505A which is the same as for W5050SQ3) uses a different LED chip, despite from being of similar production date (2023). This chip is also identical in size and surface finish, but the vias pattern and bonding pads are different. I cannot say for now what that means…