Thanks for this thread. It helped me fix my problem I hope. This is mostly for FYI.
I used the always enqueue and it fixed this problem for me. Thank you for the update as it also fixed some problems the different browsers were having with showing different current dates.
Mozilla Firefox did not have an issue displaying both. It was only Google Chrome and Internet Explorer that had a problem with the grid and list calendar on the same page for me. Once I checked the always enqueue it displayed properly in the other two browsers.
hmloneonta.org/calendar
Screenshots: https://hmloneonta.org/screenshots/