is expert ekai solo harder after the update?

I've been soloing ekai for a couple weeks and have crafted 5 MUB 6*'s and am working on my 6th.I'm using nef , gleo, yasu, and delphi. When everything went smoothly it would take about 2 minutes to finish the fight and was usually about 3 minutes. I start with gleo - and after I lay a double buff zone switch to nef. Use her s1/s3 in the double buff zone, build up sp for s1/s2 and use them. Then use a healer helper and the first phase was done.

After the last update -this is no longer working. After I use nef's s1/s2 kai still has a big chunk of health left so I end up needing to FS and s1 again to defeat phase 1 before the red marker.

I thought the chain co-abs would make things easier, but for some reason it has been harder after the update. Any thoughts on what I could be doing wrong that is making it harder? I see delphi's poison before my first s1 with nef. Is the delphi poison multiplier bug fixed?

Gleo - MUB 6*, MUB Fatalis, CC, Plaguebringer
Nef - MUB 6*, MUB Shinobi, FB, Plaguebringer
Yasu - MUB 6*, 3UB Shinobi, RR, FoH
Delphi - MUB 6*, MUB Jug, Choco, SDO