Grendel Energy Efficiency Reset While Leveling

[Venom-Nightstar]

Hello!

I have my Grendel set up for maximum efficiency, currently at 175%. My Feast ability states my energy consumption is 0.38 energy per second. I also have Energy Siphon Aura equipped, countering with 0.6 energy regenerated per second. If Im correct, I should be able to hold 2 enemies in Grendel's Gut with very minimal drain. I noticed however, that this is not the case in some instances.

Im currently leveling Grendel after some forma and I noticed that even with 2 enemies eaten, my energy is drained quickly. I regurgitate enemies down to 1, but I still lose energy very fast, as if I didnt have efficiency at all. I noticed the inconsistency a while back, but I think I might have a lead on it now. I believe while I have have enemies in my gut, the energy efficiency is reset when I level up Grendel mid mission, resetting my energy efficiency to 100%. I also notice that if I regurgitate all enemies, then eat again, my energy efficiency returns to normal. Anyone else confirm, or am I just missing a mechanic to Grendel?

Given that this issue is effectively remedied by a level 30 Grendel, its not too much of a big deal in the long run, but Im also wondering if this exists for other channeled warframe abilities as well.

Thanks for your time!