My oh my what happened to Foma 400?

I've used Foma 400 off and on for well over 20 years. I've D76, Acufine, DK 50, Clayton F76, MCM 100 and other developers. I have shot at 400, 320, last few years 200 or 250. Then a few months my negative came out thin, really thin. I thought it was camera, then developer. Today I shot a test roll using a Nikon F4, manual mode, Gossen SBC meter, from 25 to 400, developed in Clayton F76+, now it's a 100. I know that a lot of folks have shot Foma at 100, I do not understand why the ISO has dropped from 320 to 100. I may have return to Kentmyer as my walk around film, I see no reason to shoot Foma 400 at 100 when I can get close to 200 with Foma 200 and 320 with Kentmyer 400 and spot on 400 with Tmax 400.

Wow, that's bad! What expiration date on this film? I assume it's a fresh purchase, no?

Fresh just bought it a few weeks ago from Freestyle, it is Foma branded not house branded Foma. Just ran a roll of Kentmyer though MCM 100, 18 mint, Unicolor film drum, as expected came at 200 which is typical of MCM 100, about a stop loss of film speed.

Well, I have a stockpile of the old Arista Edu 120 in the freezer, so I have to go through that first.

Just have to worry about backing paper issues after being frozen for so long.

I stopped using Foma MF due to curling, still have few rolls of 400, I can test one roll to see if has the same ISO. Will use Clayton F76+ or maybe look for an old stock can of Acufine.

If this was my situation, I would first try using sunny 16, fresh developer etc. Try to eliminate everything.

Also try the F4 on automatic, has a great meter.

I've been using the new Kentmere 200, I like it. Reminds me of the old Plus-X of the 1970's.

My experience in 2022 was that the negative wouldn't print properly on photo paper unless I shot at ISO 100, regardless of the developer.
I used D76, Excel, and HC110. I still have about 70% of a 100-foot roll that's already expired, and I have no intention of wasting my time on it again.
Today, Kentemere 400 gets the job done.

I've use both Kentmere and Foma off and go for a very long time. I stopped using Kentmere a couple of years ago as I live the desert southwest and preferred a a film with a anti-halogen layer. I just found a gallon can of old stock Acufine for MF and LF that I have on hand, but will too grainny for 35mm. so I will my last 10 rolls at 100 and develop in Clayton F76+.

Reviewed my day book, I last tested Foma 400 in 2017, my ring around found 320 at 7:30 at 68 degrees in D76 stock. I later used 200 or 250 same time in D76 and F76+ and 200 in MCM 100, 18 mints, 72 degrees. The Foma data sheet indicates 250 in D76. My Gossen matches my Minolta 9 and Nikon F4, spot on.