I had the same issue and after staying up 2 days and all night I figured it out. For me it was the WP Video Plugin, but according to WooCommerce there can be many plugins that cause a problem, so make sure to go through them all.
Steps
STEP 1) Have the page that has the 404 error open in a separate tab or window so you can switch back and forth from the page to the dashboard.
Note: My 404 pages are all the ones that changed from pages to endpoints “…/my-account/view-order/…”
STEP 2) FLUSH PERMALINKS
Go to settings > permalinks >
Choose:
Common Settings > post name
Product permalink base > shop base
Click Save
Note: if these are already your settings just click save. Product permalink base will change to “custom base” after you save, it’s ok as long as your base is “/shop” . Also I did this process many times but didn’t realize each change I needed to flush the permalinks, I would have saved myself 2 days of work and now another day to get all the stuff back that I lost…
STEP 3) Refresh the 404 page
If the page does not load and continues to be 404 then continue
STEP 4) Deactivate all plugins except woocommerce
Repeat steps 2 & 3
>If the page still reloads as 404 then it’s probably not a problem with a plugin.
>If the page loads as what it should be then go to step 5 to find the plugin that is causing an issue
STEP 5) Activate one plugin
STEP 6) Reload page that was 404 but now appears to be fixed
>if it becomes 404 again then that plug in was the issue and it would be best to delete it if possible – because you really don’t know if it will ever work with woocommerce again. – you will need to repeat step 2 and 3 – and your issue should be resolved.
>if it stays the correct page (doesn’t change back to 404) then that plugin was ok – in this case repeat steps 5&6 until you find the plugin that is the issue.
notes: mine was the last one on the page and I kept thinking it must be something else, so I tried other things after going about halfway through my long list of plugins. It would have been worth the time to go through each plug in, because I delete woocommerce and some other plugins in desperation, not realizing my issue was really that I didn’t find the problem plugin and then flush the permalinks. I didn’t lose my products or orders, but I did lose some other stuff I need to now reinstall and fix the info I lost within woocommerce, but at least it’s working and I don’t have to start over.
Hope this helps you