Some very vague questions. The Middle Ages were a long period, lasting from around 500 to 1500 AD.
In most of this period the church’s attitude to Jews was that they were not to be forcibly converted to Christianity, but they were not part of the Christian civic community. This led to positives and negatives for Jews. In many countries they were freed from medieval church rules forbidding Ursury (lending money at rates of interest,) and so became notoriously rich and often hated as moneylenders.
On the other hand Jews were often subject to rules preventing them taking part in certain occupations. Other regulatory rules were often laid down by local administrations. For example the wearing of special clothing or badges (an idea copied from the Arab laws of Damascus). In some places, such as Germany, Jews lived under the protection of local bishops.
Jews supposed wealth, their keeping of themselves to themselves, and their refusal to convert to Christianity led to them becoming the targets of popular malice. Jewish traditional anathemas and curses against those who said God had a Son (not generally mentioned in histories,) became the source of rumours that Jews were a fifth column within Christendom and performed nefarious acts from poisoning wells to allying with Muslims and even sacrificing Christian children. The Church tried to hold popular enmity in check, but particularly during episodes in the Crusades, where mobs attacked Jews, they often failed. Jews who failed to convert were expelled from England, and Spain.
Martin Luther: in his “Against the Jews and their Lies,” expressed a popular anti-semitism, calling for Jews to be expelled from Germany.
Papal regulations aimed at jews or others would not count as Infallible documents.