I've fudged my "shoulder" period so that my Powerwalls intentionally power the house about 22 hours a day. Up until I got 1.36.0 (or 1.36.1), the Powerwalls would power the house right up until 3 am every morning, as desired. My Powerwalls never discharge in the off-peak period either, but I currently only have that set for a couple hours per day.
Now, it's almost like they are using the actual peak/shoulder/off-peak times instead of what I have it programmed to do as it stops around 9 pm when the shoulder rate actually ends. Maybe that's just a coincidence. However, things aren't working as they have for the past 8 months and I didn't make any changes to my TBC-balanced schedule..