Here's the tweak:
Please try the <a expr:href='"https://www.blogger.com/comment.g?" + "blogID=BLOG ID&postID=" + data:post.id + "&isPopup=false"'>alternative comment form</a> if you're having trouble commenting.
The tweak can be installed as follows:
- go to Layout then Edit HTML,
- expand Widget Templates,
- make a backup of your template just in case,
- search for
- paste the code for the tweak after
BLOG IDwith the number at the end of the URL,
- Finally save the template and double check it works as expected.
If you'd like to see the tweak in action, please take a look at my daily photo gallery. :-)