Household Sims loose existing relationship

I went back into the recovered save and tried to do the same thing, which was make two cakes, invite the teens' significant others to age them up too, age up my two teen sims, and then get one of them engaged to his girlfriend, but I experienced different problems instead. One of the sims I invited over said yes but then had to be invited again before he showed up, and then he didn't come onto the lot until I called him over (this has happened before with that same sim, but only since the Lovestruck update). Both he and the other sim I invited over could not be aged up using "Age Up" on the birthday cakes, when this worked fine the first time I did this. I could only age up random townies that were in the neighborhood at that time. I sent one of the sims I invited over home and tried to invite him back and he said yes but never appeared. The other sim I invited over did not have the option to be sent home. 

I did not experience the same glitch as before where the parent sims became strangers to each other, but I don't know if what triggered that was the other sim getting engaged which I couldn't do because his girlfriend couldn't be aged up. I also didn't save and just exited to the main menu after I had the two new issues. Should I go back into the recovered save to try again?

I do want to add that I have been playing this household since last summer, but I've saved as multiple times and this current save file is only from June 2024. I'm planning to save as again in a few days.