@jantold IF it changed then yes it does impact leaflet library. Go to inspector again F12, select the div with class progress-bar, then look at Styles tab and find what library overrides the leaflet style. In my case it was bootstrap who causes the problem. I had to bypass it by creating global style for progress-bar like this:
.progress-bar {
overflow: visible;
background-color: transparent;
text-align: unset;
}