A big thank you to Betsy of Joyful Reflections who was experiencing the same problem as I was - not being able to comment on most blogs because I wasn't recognized as signed in to Google.
She wrote that she experienced the same thing. She has been doing some marvelous sleuthing and found that she just needed to change preferences in Safari.
I went to Safari to experiment and unchecked the box above "Prevent cross-site tracking".
Lo and behold that made a difference. On my own blog page I'm shown as signed in and that continues on other blogs too.
Yeah!
Thank you to Marie of After 60 the Next 10 for being willing to change her comment selection to a pop up window so I could comment.
Thanks to everyone who commented hoping I resolved my problem.