If I were to put money on it, the issue is between ae-5.a00.dllstx14.us.bb.gin.ntt.net and ae-2.r20.dllstx14.us.bb.gin.ntt.net. I have two internet connections coming in, and on my spectrum line, I do not hit ae-5.a00.dllstx14.us.bb.gin.ntt.net and have not had issues in ~3 weeks. AT&T routing looks like:

Hop 4: 32.130.25.65
Hop 5: ae-5.a00.dllstx14.us.bb.gin.ntt.net
Hop 6: ae-2.r20.dllstx14.us.bb.gin.ntt.net

While spectrum looks like:

Hop 9: as2914.cr11-dal3.ip4.gtt.net
Hop 10: ae-2.r20.dllstx14.us.bb.gin.ntt.net
Hop 11: ae-2.r24.lsanca07.us.bb.gin.ntt.net