Why could a motif be enriched at 500bpUS and 100bpDS of TSS but not at 10kbp centered?

[charlesgwellem]

I am applying RSCENIC to analyse gene regulatory regions. For a particular gene's regulatory region and using same parameters and seed, I realise that a motif could be enriched within 500bpUS and 100bpDS of TSS of the gene but not at 10kbpUS and 10kbpDS of the TSS. I expect that since 10kbp also includes 500bp, there should be an enrichment as well of the said motif when I analyse for 10kbp centered around TSS. Please could there be an explanation for this?