His frequency is varying.There are three on the plot. The first looks like an abort. The second curls up at the end, and the third is much more U-shaped. All three are quite strong. It looks as if the power could be decreased to help with the frequency stability. WSPR is an incredibly low power mode - it will decode very weak signals. But they do need to be stable, with next to no drift.
But, all said, I am pleased with 40m/5W/LW tonight:
And even 80m has one or two interesting facets: