att fiber->tp deco slow websites?

Hi I recent got an ATT fiber, the speed test is about 500 and many websites load quickly.  I wanted to switch to NextDNS but i am only able to do it from the deco and on the actual windows/linux computers and browsers.  so i did all that, but im finding about 20-30% of websites are quite slow to load, such as certain parts of amazon and YouTube.  i think often the main website loads but then some inner frames are very slow, i thought maybe some kind of ad blocking and timeout so i turned off a lot of the nextdns ad lists but still pretty slow.  I ran the diag here:
https://nextdns.io/diag/9c2ed450-9c9c-11ee-a258-b52157f8077d
 - i think the * * * timeouts might be related to the issue but don't know why they might appear.  

Would be glad for any help.  Thank you!