Messages: 3rd party keyboard resetting

Just wanted to know if anyone else was experiencing this glitch:

1) I lock my phone while viewing a conversation in messages (a 3rd party keyboard is open when I lock the phone)
2) After maybe 5 minutes, I unlock my phone and return to the same view but the keyboard is reverted back to the Apple stock keyboard and there is no globe button to switch back to a 3rd party keyboard.

Has anyone else experienced this? I think I read somewhere that if you delete the Apple stock keyboard from your list of keyboards, this won't happen. However, I'd prefer not to do that since Fleksy and Minuum don't have a button for Siri dictation.