I play on a multi player server and am having this issue happening at base as well. Mining tunnels are dark except for the block where the torch is. Everywhere else registers 0 light. I popped into my storage room the other day where torches have been spammed and was greeted by a creeper. I can stand diagonally one block away from a torch and have that block register a light level of 7. Sure there is a temporary work around as described above but that's not realistic when you play with other people to have to reload the jar every time this happens. Nor is it realistic to have to re-light your entire base every time this happens.
I'm on a server and we started fresh in 1.14 so starting from a new world in 1.14 doesn't help. Our server admin has eraseCache as part of the server restart script and our server is set to reset nightly. It still happens. I did notice that if I travel to my base by the nether, it was mostly fine. But the other day when I was crossing the portal multiple times within about half an hour (I was working just on the other side of the portal in the nether and constantly needed more blocks), I was able to trigger the lighting issue, and then died to 3 baby zombies in my dark storage room.
We just updated to the 1.14.1 pre-release. In coming back through to my base from the portal, I did see that the lighting issue was still in full effect in the mining tunnels (y=11). In the big room where I had placed and replaced torches a couple of days ago, light values were still a little messed up. For example, a block where I had a torch told me it had a light level of 9 or 10, not quite mob spawning, but not what I was expecting for a torch on a block. When I went up to the storage room (y level around the 50s and right above the dark area), storage room was fine with appropriate light levels.