It's not so much the stem, but the collar tissue formed below it where eyes will be formed producing next year's plants. See the blue triangle mark below. That's the collar. The stem is above it. The many light spots on the base of the stem are not eyes, they are just bumps.

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Another example with eyes circled.
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After many disappointments, I now don't plant anything that isn't showing a sure eye or shoot before going into the ground. Perhaps it's time carefully unearth your tuber and see if it has signs of life. If nothing's happening, then it's time to contact the seller for a replacement.

Thanks, Pouchella, you're such a help to us novices, and we really appreciate it.
I'm like someone said once, and old gardener, but new to the dahlia addiction--I'm 73 in July.