I am having the same problem too. Since upgrading all links to posts give 404 errors.
I have tried editing and republishing posts, as well as manually changing permalink addresses, but the problem persists.
I too am unclear about what you mean by ‘updating’ the permalinks. I also tried changing the format of permalinks to see if that would update them correctly, but with no luck. Help!!
The site is:
https://historyhelp.ca/blog/