HDRI Backdrop switch button/option not functioning

Hi. Unreal Engine 5.3.2, When I try to change the image in the HDRI Backdrop (in the Outliner, the left-pointing arrow in the circle icon) nothing happens. I have the Content Browser open, the HDRI image that I want to use selected, but nothing happens, the default HDRI shows, not the new preferred choice. Any ideas on how to fix this? Thanks in advance!

I’m following along with the Bad Decisions tutorial Part 11 - “HDRI.” I downloaded the .exr version of the HDRI that they originally use. By switching over to a .hdr version, functionality returns.