Hi @Bill King,
Sorry for my late response. And yes, the timeout is caused by unsupported Hyperlink or Picture column for indexing.
Also, it is true that currently creating list items with hyperlink fields is not supported by Graph Api. I recommend you give suggestion in the feedback portal and help to make improvements. Many features of current products are designed and upgraded based on customers’ feedback. With requirements like this increase, the problem may well be released in the future. I will vote for you.
Thanks.
Have a good day.