Using the 'change flight' option under manage my booking, am I the only one who systematically faces issues when attempting to make a change online for any booking (cash and/or avios) ?

On a laptop, I systematically get stuck in the calendar view (see below) - button 'continue' does not work and loads the calendar over and over again. On the mobile app, I get flights priced in currency versus avios when I attempt to make a change to an avios booking.

I've tried Chrome, Safari and Brave - same issue.

Is there any workaround except contacting the agent?

I've been able to make a change once only previously using this option