What I did:
I have emoji defined as text labels in macOS (System Preferences > Keyboard > ‘Text’ tab)
What happened:
When I enter a text label, it does not turn into a emoji anymore though it used to work before. I don’t know if it is related to upgrading Agenda from version 1.3 to 1.4 or macOS to version 10.13.3.
What I expected: text label replaced with emoji
Things that might be helpful to know (Agenda version, OS and model, etc): Agenda 1.4, macOS High Sierra 10.13.3
Is text replacement enabled under Edit -> Substitutions?
Is it also turned on in the Edit menu of Agenda? Ie go into Edit menu, then into Substitutions.
I think the substitutions appear as spelling suggestions, rather than immediately replacing. Do they show up as a suggestion in popover bubble?
Sometimes it does 
then I press space and get the emoji.
Sometimes it does not work. It is random.
It is still working randomly in Agenda 14.
Plus the display of a unicode character (first interrobang one) changes over time when pressing the space bar on another line! Not much difference, but you wonder why.
Very strange, and you don’t see any of this in TextEdit?
No, it works fine in TextEdit and DEVONthink.
This random issue is in both macOS and iOS Agenda apps.
The change of display of the interrrobang character is in both macOS and iOS Agenda apps.
What are also the priorities when entering text? That is also a problem I am facing. It tries to correct the spelling before it substitutes though text replacement is suggested in the bar. How to force substitution before spelling and grammar?
To be honest, we don’t do anything out of the ordinary, I think the problem might be some characters in your replacement that trigger formatting in Agenda, e.g. a bullet, if it’s part of the replacement, try removing it (or escaping it with a \)
I will send you an email with my text replacement entries.
I had a look at the file and see what the problem is. You are using unicode character text, this won’t work in Agenda as we override the font etc (while we support formatting, Agenda is not a rich text editor in the classic sense). However, you’re overcomplicating things. If I just setup the textreplacements with the emojis directly:
it works just fine for me in both Textedit and Agenda:
I do notice that you need to give it time for the suggestion to appear, only then the space bar will insert the replacement.
And another thing I noticed, and this can perhaps explain the “randomness” feel and that is probably Agenda specific is that it only works if you type the abbreviation correct in one go. If halfway you make a mistake and backspace to correct, then finish the correct abbreviation, it won’t work. This is because Agenda will reload the text of the paragraph on each backspace, probably throwing away some internal state of the textview that involves maintaining the current correction. I’m afraid this is however not something we can fix, so you’ll probably just have to remember to erase a mistyped abbreviation entirely, or type more accurately 
How can I record a video of what I see happening and share it here?
The text replacement feature is working well in Typora, DEVONthink, TextEdit and Finder (I even add emojis to filenames) except Agenda so please let me know how I can help you to solve this.
We’ll take a look but as said, as far as I can see on my macOS 11 machine it works as it should. It consistently works fine if I type the shortcut without mistakes in one go and wait for the white suggestion to show before hitting space. If you don’t wait for it to appear or if you have to delete and retype parts of the suggestion it won’t work, and this might be indeed Agenda specific, but I’m afraid that’s a consequence of the technical setup that we can’t change/fix as it would not allow to do pretty much all other things that are unique to Agenda.
I’m experiencing this same issue, and it’s frustrating.
After using dedicated text snippet apps like TextExpander and Typinator for years, I’ve gone all in with Apple’s native snippets. I like that it works everywhere, and on all of my devices. But apparently it doesn’t work everywhere, or least not in a usable way.
The snippets will indeed work in Agenda, but only if you’re a terribly slow typer. It’s not a dealbreaker for me that you have to type the trigger word without any mistakes—that’s whatever. It would be ideal if it worked like it works everywhere else, but I can live with that. What makes it a dealbreaker for me, I think, is that these snippets don’t work if I’m typing at my normal pace. I have to pause for almost a second after I type a word so the suggestion can pop up.
That doesn’t work for me, Not how I have most of my snippets set up, at least. If it was just to type the occasional emoji, it might be fine. But I correct capitalization and typos with my snippets, and I want to avoid having to intentionally slow myself down just so something as basic as this is going to work.
Is this really something that can’t be tweaked by Agenda? If so, that’s a shame. I was coming back to this app after using others for a while, and it’s a shame if something as silly as this will keep me away.
I’ve been using Obsidian lately, and even though that’s a very foreign-feeling non-native Electron app, text replacements at least work over there.
