Internet drops several times per hour during day, mostly better at night

Like the subject says. Had this problem last year and technician found ancient cable run to house, replaced it and fixed problem. I upgraded a couple months ago to 4K X1 boxes (and therefore all coax splitters have been removed from system), 1 gig internet plan, and home phone. Bought new router and voice-compatible modem. Everything was fast and good until last week. Every time the signal drops out and I try the Xfinity Assistant on the app, the signal is back before it gets tested so the app says it's fine. Checked all connections, restarted all equipment multiple times. Log shows many T3 time-outs. Getting tired of crashing out of Teams meetings.