What usually happens there is that the sites do not work because the JS wasn't downloaded and interpreted yet. That happens more often when all the images are always downloaded when loading the page. Lazy loading of images is one method to address exactly this problem :)
My definition of broadband is correct, and 1.8Mbps does not match it. Where I live 1.8Mbps just is not legal broadband. In the US that also does not count as broadband anymore, see https://broadbandnow.com/report/fcc-broadband-definition/, and it hasn't for over a decade.
It's partly JS, it's partly the data populating the tables.
I must say that the FCC really messed up by redefining broadband when they were the ones that had originally defined it in terms of RF spectrum usage. Here in Canada, the telecom regulatory body set the Basic Service Objective to be 50 Mbps download and 10 Mbps upload. They didn't try to redefine what broadband is and overload a term that already had meaning in the telecommunications space.
Personally I think latency is more important with modern internet connections. 10 Mbps is still quite usable for a lot of things, but not if it's 500ms RTT via a satellite. Sadly most telecom regulators ignore latency.
My definition of broadband is correct, and 1.8Mbps does not match it. Where I live 1.8Mbps just is not legal broadband. In the US that also does not count as broadband anymore, see https://broadbandnow.com/report/fcc-broadband-definition/, and it hasn't for over a decade.