added 

note=at time of mapping the northern end of the highway there used to be a 237 road sign (cycle path), whilst there was no sign at the southern end. - see https://www.openstreetmap.org/note/5271327

then

and ouch, I wanted to recommend reporting it to local government
In Poland there would be decent chance it would be fixed (and how much costs to remove nonsense sign?)

personally I would remove that highway:backward=cycleway but as remote mapper I will just close that note