Consistently, when I type "10pm", the Message+ app changes it to "110pm".
It's been this way for a long time, and certainly through the last few versions of the app. I'm currently using version 6.6.7.
The highlight will then go away and the number 10 will have been changed to 110.
What device, make/model, are you seeing this issue on? I have a Droid Turbo 2 and I cannot duplicate your issue with Message+ v6.6.7. When the 10 I type gets highlighted, I'm not presented with an option to replace it with an emoji. I just keep typing what I want, e.g. pm and 10pm is what stays. I do have 'Enable Smart Emojis' turned ON, if that means anything.
The device is a Samsung SM-G930V.
When the 10 I type gets highlighted, I'm not presented with an option to replace it with an emoji.
Nothing happens when you tap on the highlighted area? It's supposed to show relevant emojis that you can select to replace the highlighted text.
Ok, if I tap the highlighted '10' two emojis pop up to be selected, a '10' in a box and a smiley face. If I don't choose either, but continue typing 'pm' then '10pm' is the result. Again, I cannot duplicate your issue. It may be an issue with the app version on your Samsung. You probably should go into Settings and select 'Report a Bug' if you have that option. It should go to the Developers of that version of the app.