Is this yeast more sensitive to bad water or chlorine? If I smell it I think it has chlorine smell. Someone once told me they let water stand in buckets for awhile. I have not had this before with kit yeast packs?
The problem with your logic is that you aren't looking at what is really going on.
The formation of Chlorophenols has nothing to do with yeast its a chemical reaction between any Chlorine in the water and Phenols from malt (mostly extracted from husks, maybe some from hops to).
Sitting water in a bucket or even boiling all your water will reduce free Chlorine, it probably wont get rid of Chloramines, most municipal water is treated with a mixture of Cl gas and Chloramines these days.
A Carbon filter will remove both, as will adding some metabisulfite.
Comparing the little 6g kit yeast with an 11g pitch of US-05 isn't really all that reasonable, US-05 is more attenuative (eats more sugars) than most other dry yeasts, tends to give a lower FG and if used properly should leave less yeast flavour's in the finished beer. Most yeast flavours are made early in the process while the yeast is reproducing so more yeast at the start means less time making yeast and flavours.
Actually that's why there is a recommended pitch range, too little = slow and estery, increased chance of infection... too much = little yeast flavour, reduced bitterness, some faults from unconsumed lipids... its a range that 6g doesn't really fit into.
I suspect part of the problem is that using better yeast and more of it has made better cleaner, even crisper beer, it has also left room to taste other faults that were always there, just hiding behind a bunch of other flavours.
Mark
Edit
Nothing to do with stainless steel, in fact its less likely to cause problems than anything else (well glass might be better).
M
like covid 
effects taste apparently.. don’t know it’s weird ...
