The "tiny, reddish leaves" would indicate a problem at root level. It could be due to the roots of the maple or it could be something eating the roots. I don't know if vine weavil attack Sedum or not but the symptoms are the same. I would lift the Sedum and inspect it. If the roots are clean the replant in a different place.

Thank you. Do you have a suggestion for a low growing ground cover? I have them growing under euonymus trees so I want something that would hug the ground. I live in New York State, zone 6.

Ajuga makes a good ground-hugging low growing plant: mine have dark 'purplish' leaves, but you can get various shades (and it has blue flowers in Spring/Summer).

I use normal soil in Sedums and they bloom pretty well.

I personally would dig it up from that position and either replant it some where else or pot it in 'normal' soil. One of my Seedum plants, did not do as great as the one I left in a pot this year so I have put it in a good-sized pot and given it new compost for support. Hopefully, this give me a healthier more vigorous plant next year.

As for good ground coverage plants have a look at Campanula and Creeping Jenny.

I certainly will Gorgeousmam and I appreciate your advice and input. Thank You.

Thanks Everybody for all of your comments. I suspect the Silver Maple tree is hogging all the nutrients. I love the bright blue flowers on the Campanula. I just hope it doesn't suffer the same fate.