OS: Ubuntu 20.04 desktop 64 bit OS;
libwebkit2gt: 2.28.2
steps:
1. launch epiphany browser, enter URL (Citrix storefront URL)
2. press key "a" for 10 seconds in input box,  after press up the key "a", it still enter extra "a" (s); 
e.g.
              key down "a".....key up "a"
                      aaaaaaaaaaaaaaaaaaaaaaaaaaa
              expect: aaaaaaaaaaaaaaa // when press up "a", it should not enter extra chars.
libwebkit2gtk 2.20.5(Ubuntu 16.04 desktop 64 bit OS) doesn't have the issue. 
libwebkit2gtk 2.24.2(ubuntu 18.04.3 desktop 64 bit OS) doesn't have the issue, but could repo the issue after upgrade libwebkit2gtk to 2.28.2.
firefox and minbrowser doesn't have the problem.

Thanks!
Wendy