[4] Struggling with HGSS RNG

I've successfully rng'd lots of shinies and perfect IV pokemon in Emerald and Platinum, but having no luck with trying to rng in HGSS.

When I try searching Irwin's calls, I usually get 0 calls in return and I have absolutely no idea what I'm doing wrong, I've tried expanding my search calls, re-trying different target delays and dates, and still keep getting 0 calls.

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If it helps, I'm trying to rng in Route 32 for a shiny mareep, Japanese Heartgold, DS Lite. I've verified my TID and SID through PKhex and it matches in pokefinder.