Because of the decoding happening in multiple steps, you need to percent encode the percent to get around this.
session relevance
"%22"
rest query
https://brollytest:52311/api/query?relevance=(%22%252522%22)
on the first decode pass,
the outer %22 turns into "
the outer %25 turns into %
Then on the second decode pass you effectively have "%2522" which converts to a "%22" and finally to a """