If you are using a custom theme or have a copy of activate.php in yourtheme/buddypress/members/, you will need to update it.
Please open the file yourtheme/buddypress/members/activate.php in an editor and look for a line like this
<input type=”text” name=”key” id=”key” value=”” />
Change it to
<input type="text" name="key" id="key" value="<?php echo esc_attr( bp_get_current_activation_key() ); ?>" />
That will auto fill the input key.
