Good video, and good work! It is very easy to over-voltage these MPPT units which are rated at 100V, but can take over a 1000W input at 24V... I have seen this exact problem before; every Epever MPPT I have seen fail, failed at the MOSFETS or the 330uf 100V capacitors. Withe the FET failures I assume due to the panel exceeding VoC in our very cold Canadian weather when it's sunny out, and the MOSFETS going into avalanche, heating up, and dying. INFINEON IPP041N12N3GXKSA1 may be a better replacement with a 150V rating instead of 100V. I have not tested this but it should work. I would also replace the large 330uf capacitors with 150V or higher ones. Panasonic 330uf 160V EEU-EB2C331 is a better replacement for them which I have used many time successfully.