Hello,
Maybe the following OSS note should be implemented as well:
Note 1829926 - RFW:Activities are displayed incorrectly.
Also, be aware that sometimes search results are cached to save performance. So if you use the breadcrumb navigation for example, when you come back to the account overview page the system might not reread all data from the database for every assignment block... So to be 100% sure that you're not facing a caching issue, it is a good idea to close your browser and start a new session to see if the table contains the newly created opportunities then.
Cheers,
Nicolas.