Does this have anything to do with the extensive and happening now or very recent shutdowns of several california refineries?

Yes. Between 2020 and present The refining capacity in California declined by 35% from 1.9 MM BPD to 1.2 MM BPD with the closure of 4 refineries:

Marathon Martinez (2020) converted to renewables. Crude capacity 157 MBD, Renewables capacity 48 MBD

P66 Rodeo (2022) converted to renewables. Crude capacity 120 MBD, Renewables capacity 50 MBD

P66 LA (2025) shutdown. Crude capacity 139 MBD

Valero Bencia (2026) shutdown. Crude capacity 145 MBD

The California Air Resource Board (CARB) has promulgated a revised Cap and Invest rule that threatens the viability of the remaining refineries. All the remaining California refineries have sent CARB, the Governor and the CA legislature letters pointing this out.

California is now a net importer of gasoline following these refinery closures.