I mentioned in my previous post that updating automatically to 14.21 looked to have fixed the issue.

I forced a downgrade to 14.20 and see the issue in the multiplayer map. Saved it as is in the screenshot and have uploaded again. I can replicate the issue in any save or new game that is 14.20.

Steam updated before I was back at my computer to upload. Loaded Ribbon world which is now fine with pollution. Attached along with another map which I haven't loaded since the update in case that helps.

Cross post from https://www.reddit.com/r/factorio/comments/5f999j/bug_pollution_striping_issue/

I've been dealing with this issue where my pollution shows up only in stripes. I have the issue with single player and also in multiplayer games hosted by another player. Used to not be this way. Before ...