Most often I play on a Firefox 45.0.2 eme-free.
Sometimes I play on another browser or another computer and I will try to check there for the error. I can tell you also, after posting that last screenshot I continued playing LC and didn't see the error again. And that is consistent with prev experience, where only occasionally I would check and only a percentage of those checks would note an odd subtotal.
Lost Cities was new to me so it took a while for me to become comfortable with the scoring and puzzled enough to look further when I happened upon it again.
UPDT:
If it's the type of issue that you think may just be down to old tech, then I have to be even more judicious about the items brought to your attention. Most sites I use including game playing don't seem affected however your site is newer plus you have probably more advanced AI. My experience is that most things work fine for me and when something doesn't it's fairly obvious as to why. But if the tech here may result in more nuanced issues... well, all I can say is that my intent isn't to cause you unnecessary work or pointless investigation on old tech vs new tech issues and if that is what's happened I'm sorry.