I attempted to use the roll20.net site in Chrome (regular and desktop mode) on a Samsung Tab E, and noticed that unless I had the map zoomed all the way out, the map image did not scale according to the dimensions I had set for it (which I had done painstakingly to get the printed hexes to align with the hex grid). Even odder is that at certain zoom levels, the map would get distorted, where one side of the screen was the correct aspect ratio, and then past a certain point the width would increase dramatically. This seems similar to an older bug I found related to iPads here