I have been following up the experimental build, as for now I have is 8696, but yesterday, not sure since which version, I can no longer use angle bracket keys to browse the previous or next page in inventory.
I believe my keyboard is working fine, because I am still able to turn page in advanced inventory by using “>” key.
I have tried to download and unzip the game quite a lot of times, start new character, and the problem still persists.
I thought it was changed to use tab and shift+tab some time ago. Try those keys since I was playing last night and they worked. At least I’m pretty sure they worked, a lot of it is muscle memory for me by this point so I wasn’t consciously thinking about the key presses to navigate the inventory so there’s a slim chance I’m wrong.