This might've already been fixed, but in case anyone else searches this issue:
I created new books for an existing company and set them up as a sole proprietor in QB, and there wasn't a Retained Earnings account anywhere showing prior years' RE. Instead, QB called the account Member's Equity. Clicking on Members Equity showed the "retained earnings" closing entries I was looking for. I'm willing to bet your "retained earnings" account is the one called Shareholder Equity on that screenshot. They're all pretty much the same thing, just different names.
For sole p's, the single owner owns 100% of the company, so 100% of your P&L that flows into a "retained earnings" -type account IS the owner's equity. It's usually called Owners Equity or Members Equity (although Members Equity is more for partnerships), and you generally don't have a separate account called retained earnings because they're the same thing in this scenario. If you had a RE account for P&L activities, you'd distribute the entire balance to Owner Equity anyway, so it wouldn't serve any additional purpose. You could have additional accounts for Draws/Contributions, but those aren't tied to P&L activity.
This differs from, say, a corporation, where there are frequently multiple "owners" (the "equity holders", or "shareholders", since corporations don't have "owners"). For corporations, the P&L related account is called Retained Earnings. The final P&L number flows into RE, where you then have to manually distribute the RE amongst the equity holders depending on their ownership percentage in the company. It acts like a collection point so you can then make all your equity distributions. So there's usually multiple accounts involved - the RE account and the individual member equity accounts, which are Shareholder Equity / Member Equity.. or Shareholder Distribution / Member Distribution. (Ideally a member should have their main Equity account with subaccounts called Distributions, Contributions, and Draws.. "distributions" are just the part of their equity that comes from the P&L. Total equity is made up of all collective activities.) So the names change and multiple accounts can exist, but there will still be that one account in QB tied directly to P&L activity.
If everything else in QB is set up correctly, the retained earnings you're looking for will be one of those Equity accounts, it just might be named something else. There should only be one of them tied to P&L, which collects all activity even if you imported stuff. Swapping company structures shouldn't change anything but the name used on the equity account, because the swap applies changes to the entire company file, for all years (unless the set Closing Date affects something, so maybe play with that date?). I could see QB creating both an Owners Equity and a RE account if you're trying to merge/import QB data with different company structures, but that would be glitchy. The info being imported should adopt the settings of the company you're importing into. But, I've never actually tried it. Maybe try changing the company structure on the one being exported so it matches the structure of the other company, so everything would have the same settings and should merge without issue. It could be that the equity accounts tied to P&L activity in the two companies are named two different things, which might prevent QB from being able to merge them straight from the import (unless Account names match perfectly, QB creates both names when merging). If you can find two such P&L related equity accounts, try manually merging them by giving them the same name.
For anyone wondering what this equity account looks like, it should only have 1 Closing Entry for each year, created automatically by QB, and the number on that entry should match the final number on your P&L report (make sure both reports are either in Cash or Accrual or they might not match). Anything else is not your "retained earnings" -type account.
