Honestly... You're the first person I've had get there (or that has told me). I plan to implement all of the chicken-related boosts and bonuses (the description of immunity is accurate but it doesn't do anything right now, and all of the phobias will increase damage taken from chicken attacks) in my next patron build. I'll take a look at why something would break after getting the title.... Unless I made a dumb mistake (totally possible), it shouldn't cause any additional problems...
I tried to ignore error today, doing so you can see Chicken immunity title, but +25 intelligence doesn't move to stats.
Can't say anything from other bonus, because fighting against chicken is that hard. I needed to redo by going back multiple times to not get crit dead by first turn, and got error as reward to first 2 screen after killing chicken, so it's not only once. (I think that's from not only killing it, but also from item reward, i noticed reward only by looking in inventory.)
Also after getting that title, there will be error every time you die, most likely because game tries to give upgrade that doesn't exist to title.
Maybe if you choose to fix those you might want to give lvl 4 to shrine (as that too ends to error when you have first succeed kill chicken (only possible to get lvl 4 is killing chicken)
Don't know if anyone has said about one thing that i noticed nearly immediately when i started whole game, after first death, If you try get better starting stats, don't skip first 5 days, as even if you have upgraded saved stats, they stay like they where in first life. (also least at now before getting all stats least once 30 (try get all same time 30
) don't skip, you only get better stats)