"02/21/20 21:30:25 | GPUGRID | Tasks won't finish in time: BOINC runs 99.8% of the time; computation is enabled 99.6% of that"

I do not understand the why behind this message. In 24 hours I only switch off for a few minutes in order to blow air through the cooling fins. Dusty environment. Have been crunching WU's quite happily so far. Has anything changed?