Bolts not updating to 1.9.1

I am using pod 'Bolts', '1.9.1'. I am getting error CocoaPods could not find compatible versions for pod "Bolts": In Podfile: Bolts (= 1.9.1)

But if I do pod 'Bolts'. I am getting Bolts 1.9.0. What can I do to get latest version 1.9.1?

I am on OS 10.15.4 and cocoapods version is 1.9.1