I created a one2maylist with some buttons like the code below:

<button  string="Resend" name="send_mail_event_reg_link" type="object"
    class="oe_highlight" groups="base.group_user"
        attrs="{'invisible':['|',('stop_sending_mail_visibility','=',True),'|',
        ('status','=',False),('resend_mail_visibility','=',False)
        ]}"><span id="oe_resend_selected_mail">cccccccccccccccxxxxxxxxxxx</span>
</button>

Well here not the problem with any functionality, But I tried to make some HTML elements inside the button as usual flow. But it didn't get an effect and also I made a custom class to the button, this also doesn't get affected.

Any one knows why this behavior and these buttons are now on the one2many list view.

NB: Please don't answer if you don't correctly know the answer. Because Now some users are trying to make unwanted comments and answers which don't help, and only for upvotes. This actually blocks to reach the question to someone knows and these unwanted comments and answers make them avoid such questions.

If I try to delete the unwanted comments odoo response as http_response error or 400. like here