Upcoming link has unnecessary "?" in URL

If you visit a page with a list of gigs, the URL may be something like this:

https://example.com/gigs/

But then if you click and archive year and back to Upcoming, the URL becomes:

https://example.com/gigs/?

Having this non-canonical URL is bad for caching and SEO.

https://www.ads-software.com/extend/plugins/mf-gig-calendar/