I have many publications in my profile that I had to add manually, but ResearchGate seems not to recognize any of them sufficiently to create links to the online full text (and other info) that is readily available for all of them (Google Scholar, for example has links to every one of them).
Will ResearchGate eventually find and connect these publications? (Is adding this information manually myself the only option?)
ResearchGate will try to suggest papers that closely relates to your name provided. It will mostly suggest papers whose details are in its own repository (and probably some others). It does not have an effective crawler like Google Scholar.
I would consider adding them manually to be the better option.