There are scant reports handed down to us from the medieval period regarding what we today call UFO encounters. These are noteworthy and something unique in each caused their retention. The Japanese ones appear to have the same message of respect for a supreme being and may well be an insertion. This still led to the stories been kept.
Add in the Bronze Age reports in the Bible and the reports out of India, we get the same picture of actual communication over all of history. Our limited textual material merely acts as a sampling device that shows just that.
Such communication is ongoing as well but not visibly studied by any agency that we can recognize. The actual content reported remains plain vanilla envelop but likely represents a prepared statement. Where intelligent dialog took place we got important information including a strong confirmation of how gravity can be manipulated. They are willing to share information.
As reported as well it appears plausible that government agencies do have access and have been pursuing obvious research lines. However governmental secrecy regimes has stifled the advance of this science.