All of the player profile buttons, from attacking to sending a mail seem to be requiring a few clicks to activate. This is fairly annoying when trying to be quick on attacks or revives. Refreshing the page seems to sometimes fix it.
This seems to be the case only on my IOS device. Browser on desktop seems to be fine. I have a guess that this started with the version 26 upgrade and as such may be related to the the other bugs reported for this version.
I'm currently at 26.1 and that hasn't fixed it.
I recorded a short video showing the problem on both PDA with some userscripts and Vivaldi without: