When upvoting a thread from the thread list without entering into it, you should see a blue expanding circle around it temporarily, the arrow will turn blue and the displayed count will increase by one. However, I've encountered what seems to be a bug where after a duration of time (or possibly due to endless-scrolling and loading additional threads breaking a voting script) if I click the upvote button then it only causes it to turn blue - no temporary blue circle, no count increase. Entering into that thread after this happens shows that my upvote did not count. When this happens you can either go into the threads themselves (or open it in a new tab temporarily) and upvote it from within, or you will need to refresh the main thread list page to return the voting script to functioning properly. You will need to then return to where you left off in the list and upvote the thread if you didn't go into it manually to upvote it. I plan to do more extensive testing to see how many infinite-scroll thread loadings it takes before it bugs out or see if it is time-related to where it may be related to a browser function of releasing memory from a tab and bugging the script or if it is possibly a browser extension (like uBlock/noscript/uMatrix) causing it.