Motorola MD400 2.4 GHz cordless phone button key hard to press

All,

I have a Motorola MD400 phone system. I have 3 phones plus the base
station. On all 3 phones the buttons have become a pain to push and
get them to beep. You push the button, push and push ... and maybe if
you're lucky it will beep making the tone for the number. I seems
like a product defect.

I've checked the motorola support website... they are not listing it
as a known issue.

Anybody else have this experience?

Bob