I heard back from them last night. They're saying there's 2 different reflections/halos in there. The tight inner ones around Sirius are caused by the filters, the larger reflections (with the spider vanes showing) are caused by the MPCC. Kinda what we already knew, but the good news is that they're sending me out a replacement set of "no-halo" filters!
Must thank you guys again for your links and help.