The official story is that the Two Plus Four Agreement made Germany become fully sovereign. See Wiki link below.
The two-plus-four-treaty had the function of a peace treaty, but it was not called a peace treaty.
If you would not consider it as a peace traty we would only have a cease-fire :o
In this context it might be intresting that the Enemy State Clause of the UN against Germany might be still applicable. It is a passage of article 53 and 107 as a half sentence of article 77 of the UN Charter.
https:// en.wikipedia.org/wiki/Treaty_on_the_Final_Settlement_with_Respect_to_Germany