Exchange GAL lookup - only works on Samsung dialer

[Android Central Question]

I have an S8+ (AT&T, Android 7.0, Samsung Experience 8.1) and would like to replace the stock dialer with something (anything!) better. Currently, using the dialer I can start typing a name in the search bar and it will return names/numbers from both my contacts list and the Exchange Global Address List for my company - very convenient. However, I have tried many dialers from the Play store (drupe, Simple, Truecaller, ...) and none of them will search the GAL. I am not trying to sync the contacts (i.e., dump my company's GAL to my phone), just want to be able to do a lookup like I can with the stock dialer.

Any suggestions?