There's a Royal Fount directly after the Resin Cast bar, please make sure you top up the tank right after that attack before the Oppressors perform their Lasers + Gunnery Pods + Preys.

If you do not top the tank back up from that particular Royal Fount, you'll always be 1 GCD behind, and that can be extremely difficult to work with due to the tight timings of Prey + Royal Fount + Hyper Compression.

Also Synastry.