You can’t stack too many commands on Schlage locks. Need to space them out by about 10 seconds or so. There is talk in this post ((Enhanced) Z-Wave Schlage Touchscreen Lock) about the slowness. Maybe adding a slight delay will help.
Also look at the IDE live logs it will show if the commands are even being transmitted out. What you are seeing in the app is the log from the smartApp but not necessarily from smartthings sending the command. (https://graph.api.smartthings.com/login/auth)
I had an issue with my locks a few days ago, the commands never was sent. I had to remove and re-add.
Why not just use the autolock function?