Split text message screen

I switched from Samsung Galaxy to an iPhone a few days ago. Called tech support and after talking to 4 different techs I was told the screen I had on my new phone was most likely a glitch.

When texting the screen displayed the language keyboard on the left side and the emoji keys on the right side simultaneously. I haven’t downloaded any 3rd party apps and the phone was bought brand new from a T-Mobile store. I’m still trying to get used to this new phone so I just assumed this keyboard was standard/an option. At some point last night while sending a text I switched the keyboard to the full screen QWERTY keyboard and now I can’t get the previous keyboard back because there isn’t an option for it.

Just wondering if anyone has experienced this and if so were you able to go back to the split screen keyboard?