Left headlight intermittent

Hi all, Looking for some advice here. I had my PTC heater replaced around two weeks ago (2019 model 3) and since then my left headlight has been intermittent, it seems to work in the day time but doesn’t work at night time. I booked a service appointment and they have quoted £900 for the repair. This started almost immediately following the PTC replacement, perhaps a day or two later. Is it possible this issue is linked, or is it a coincidence? I don’t want to pay £900 for a repair (especially having just paid £1200 for a new PTC heater) if this issue was caused following my prior service. If it is just a coincidence, is there a cheaper fix for this? I’m thinking perhaps some DIY fix if it isn’t too difficult? I can provide the error code from service mode if that is any help. Thanks in advance