Ludwig, thank you for your response. Okay, I am not so sure that posting from my iPhone would make any difference in my case, because I have a static IP address. So whether I use my iMac or my iPhone to post to Instagram, the same IP address would still be logged by Instagram.
Second, I never post from my iPhone. My graphics are not selfies. They are thousands of images I have created in Adobe Photoshop. These images are not even on my iPhone. Aside from that, my images always contain a lot of text, including a number of links to other locations on my website, which provide supporting information for each image that I post. In short, to be able to do what I do on my iMac in my WordPress setup, would be very difficult to do on my iPhone.
What you still haven’t explained to me, and what I still do not understand, is why I don’t have a problem with posting my images on Instagram while using the Flume app. This is from my iMac. I just posted thirteen images on Instagram — via Flume — without a problem. If I have been banned, or flagged for spam, or have some kind of bad reputation that I am not aware of, wouldn’t it be impossible for me to post images using Flume as well, being as I have a static IP address?
I have been posting to Instagram for a number of years now, and it has always been the same kind of material, and in the same quantity. So I don’t understand why this should be happening now, unless Facebook has made some behind-the-scenes changes to their API and algorithms which is now negatively affecting some of us.