Trailing space after text replacement / keyboard shortcut is gone on Mac

In the last week or so the trailing space after a text replacement is gone in some apps but not all. For example, when I type ppl and hit the space bar it both accepts the text replacement of ppl to people AND adds a trailing space so I can keep typing smoothly. Now though, hitting the space bar only replaces the text but doesn't have the trailing space so I have to press the space bar twice or else the words are smashed together.

Hmm, seems like a bug because sometimes it works and sometimes doesn't -- e.g. even in writing these sentences it worked with converting "wk" to "week" with the trailing space but now it is not working just seconds later. And it seems to be adding the spaces to the end of my sentences I'm realizing where there are a whole bunch of spaces. It happens the worst/most in Gmail on Chrome, but Slack was working earlier and now isn't. This is exclusively on my MacBook Air. I got a new one today and noticed it's happening here and on my old Air.