iOS 11.4 keeps changing keyboard

[jw2002]

Ever since upgrading to iOS 11.4 on my iPad air, my most recent selected keyboard won't stick. For instance, if I go from an app to the emoji keyboard and type a symbol, go back to the app, and then try to go back to the keyboard, the keyboard ends up on Chinese or Spanish, etc. Then I have to cycle through all the keyboards using the globe icon until finally the emoji keyboard is shown again. This was not happening in previous OS versions. Is there by chance some new, hard-to-find setting that has enabled this undesired behavior (akin to key flicks or auto play videos in the app store) that I need to go in and turn off? Thanks.