Same bug that was reported in C3.
Tested by adding Solid to the Pigs in the Line of Sight example.
Line of sight to object does not return anything if the object has the solid behavior.
I've no idea which C3 bug you're referring to, you didn't even link to it. Please always follow the full bug report guidelines otherwise it's impossible to help.
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It was fixed in: construct.net/en/make-games/releases/beta/r154