Having an extremely frustrating time migrating data during upgrading to 1Password 8

I have been using 1Password for many years; still on v7, looking to upgrade to v8. However, I cannot migrate my data from my 1P v7 standalone vault:

If I tell the 1P v8 installer to import my data (with 1P v7 running):
1. It stays on the "Waiting for data to be migrated" screen
2. 1P v7 opens a pop up offering me a 3-year 50% off offer to sign up. However, the offer code is expired
3. If I remove the code, it lets me move forward with only my email, but then it complains there's a 1Password account associated with my email address (which is correct, I created it this morning)
4. At this point, there is no option to continue migrating my data on v7, and the installer for v8 is still waiting

If I manually export the data from 1P v7, then install 1P v8 and try to import my CSV:
1. If I select the iCloud CSV, 1P v8 says it contains no items, and nothing gets imported
2. If I selected the non-iCloud CSV, it gives me an error message saying "The provided CSV contains an unbalanced quote", and it fails to import anything

On top of that, if I re-install 1P v7 (after it was replaced by v8 during installation), it no longer allows me to add new items (all Add options on the menu are greyed out)

So, I can't continue to use v7 as I had been for years, or move on to v8. What am I supposed to do at this point?

1Password Version: 7.9.11 + 8
Extension Version: Not Provided
OS Version: macOS 12.6.8
Browser: Safari