Dynamic Lighting gone haywire on 'Plus' account

I've been running the D&D 5e Storm King's Thunder module and bought the Roll20 pack with the player maps including dynamic lighting. It used to work fine, but two sessions ago we started noticing problems. We were on the Temple Of The All-Father map and suddenly anyone who had darkvision appeared to be emitting light out to a ridiculous radius. Double-checked the settings, everything was correct. Exited the game, restarted, got the players to do likewise, nothing. It didn't kill the game, but it was a bit of a pain having to remind the players that their characters couldn't actually see most of what was now visible to them. In today's session it got worse. I set up the PC tokens with the appropriate darkvision and light sources, but the players couldn't see anything. The map was entirely black for them. When I exited the game and came back in, none of the changes I had made were saved. I tried this several times, adjusting the dynamic lighting settings, saving, players saw no change, I exited and rejoined, none of the changes were saved. Only thing that allowed them to see the map was turning off dynamic lighting. We eventually ran the session that way, but obviously I'm not happy given that a large part of the reason I bought a Plus account and paid for the module was to have access to ready-made maps with dynamic lighting. Can someone please help out before I have to start looking into refunds and shifting to another system? Foundry is looking mighty good right now.

Did you try to go into game Settings and try Convert Lighting? My old campaign doesn't even show the option for the new tinted light feature, so games need to be upgraded for the new lighting update. No garanteees it wont break things even more, though

This is not a problem being reported elsewhere, so odds are that it is a procedural error, or something unique to your setup. Can you post some screen shots, along with a step-by-step way of duplicating the phenomenon? Also, I'll post the standard troubleshooting and a DL checklist below the line. Could you please carefully work through these steps of our guide to  Solving Technical Issues ? Step 1: Make sure to use the right browser Please check if these issues persist when using both Chrome  and  Firefox. Step 2: Ensure that there are no extensions/addons interfering with Roll20 Please disable  all  add-ons/extensions. Step 3: Clear your cache If none of the above succeeds, please thoroughly work through  Step 4 .  (Don't forget the complete Console Log!) Here's a "why can't my players see anything?" checklist. The important thing is to verify . Don't assume. This list is written with GMs in mind, but can help players work through issues with their GM. The token is on the VTT It is assigned to the character The player has control over the character The token is on the Token/Object layer It is not blocked off by DL lines from seeing the immediate surroundings Make sure the player is looking at their token's immediate area. Shift-Click and hold on the token to pull the player's view to that area. If Fog of War is being used, that the area the token is in has been cleared The player has not been Split from the Party (Check the Help Center if this is unfamiliar) If Dynamic Lighting of any kind is being used: The token has sight turned on The token has a light source, or Nightvision (UDL) or personal light (LDL) In UDL it may be necessary to move the token one square to get everything working, or in extreme cases, refresh the (user's) page.