Are Google Apps Script execution timeouts different for trigger executions and editor executions?

Question

I have a Google Sheets budgeting spreadsheet that uses the javascript functionality to automatically add a new sheet for each week (based on the current date when the spreadsheet is opened). I have been using iterations of this script for years now.

Just recently the script started timing out on me. [EDIT: In the past I have used this same script to add and update multiple sheets at a time. Now I can't seem to add even one sucessfully.] However, if I open the script editor and run the function from there, it works perfectly. In the execution log I can see that a trigger execution times out at about 30sec, but an editor execution works every time, and takes about 40sec.

While typing this, I noticed on Google's quotas there is a 30sec runtime limit per custom function. Why is it different when triggered from the editor?