Polyomino zoom problem/bug with Chrome

I used to play on LG with Chrome, it was a 28.x version.
When it happened to me to update it, because it was too old, reaching the 33.x version, I found that playing Polyomino completely changed the feeling.

To keep the whole board in the screen, I used to zoom out the page (90%). When the page is not full 100%, the checkboard of Polyomino (I think t does not happen with other games) miss the white borders, and stay all in contact one with the other.

Here is what I see now:

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Before the Chrome update, the cases stayed well divided and did not make contact one another.

Thanks, Richard

As you can see, with the same zoom level, on chess (for example) there are no problems.

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If you reset the zoom, do the lines on the Polyomino board reappear?

Yes they do. Lines appear in Polyomino only when I see the page with 100% zoom or larger. They disappear when going smaller than 100%. While if I change the zoom level for chess or reversi everything is fine at any zoom level.
I tried this on different virtual machines and it happens on later (maybe 30+) versions of Chrome, everything was fine with Chrome 23.