Rural rights of way revisited

Rambling across the fields and forests around Jakubowizna, I'm often walking on farm tracks. The assumption is that they are public rights of way, until one meets a fence, a gate or a wall. But such signs? 'Droga prywatna zakaz wjazdu'. Can I continue along this way? I'm walking, not riding, so the word 'wjazd' here isn't relevant to me (if walking through here were to be prohibited, it would be zakaz wstępu). Is this sign legitimate, or an attempt by a nearby landowner to curtail through traffic by claiming ownership of the road? If this were my land, I'd simply fence it off at either end. Having said that, I've been waiting since August for a builder to fence off the land I bought last year and delineated by a geodeta in June. 

Back home, I check on the e-mapy service (which is excellent - it covers the whole of Poland and shows every separate plot). This shows an ambiguous situation, where according to data from the gmina (third-order administrative division) that this is a road (shown below with the two 'no entry' signs at either end of it). But the fine light-blue lines show that this road does actually run along and through plots that are privately owned. Can anyone tell me what the legal status really is?

Below: the same, but on the Google Earth satellite view.

Below: this sign (on the road running left-right along the bottom left of both maps, below the lower 'no entry' sign) is on the road from Jakubowizna to Machcin. I'm now making sense of why it was sprayed. The left turn into an unasphalted track is the way from the road to the first 'no entry' sign. Turning left is the short route to Adamów Rososki. It seems the householders owning the property rights to the road are unhappy about it being used - mainly by local farmers, I would guess. The long way from Jakubowizna to Adamów Rososki is at least properly asphalted, so a less bumpy ride for cars.

I am still puzzled by the naming of settlements around here. According to chynow.e-mapa.net, the area to the immediate east of Jakubowizna is called Nowe Winiary, but I cannot find any houses bearing a number assigned to such a settlement - nor does Nowe Winiary appear on Google Maps. On the ground, the local signage refers to the area as Machcin II (and indeed Winiary on the the e-mapa is signed as Machcin I). 

UPDATE 31 OCTOBER 2021: Situation unchanged, unresolved, signs still there.

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