13 year old male with no past medical history who was referred initially for microhematuria. After evaluation, patient was noted to have proteinuria, non-nephrotic range. UP/C ~1.7. Patient stated he did have gross hematuria associated with URI symptoms. No edema, normal blood pressures, normal serologies, normal serum albumin, negative ANA, negative Hepatitis panel, and both parents negative for hematuria. Biopsy revealed primary membranous glomerulonephritis (positive staining for PLA2R).
Patient was started on Lisinopril with UP/C now 0.7 (however, yesterday ambulatory UP/C 1.3 and first morning UP/C 0.6). Patient no longer with tea color gross hematuria, but remains with glomerular microhematuria.

Not typical presentation. Patient only on Lisinopril.
Question is etiology of glomerular hematuria?