I'm not an electrician but your "3 gauge copper to 6 gauge aluminum wire" comment and pictures possibly showing no conduit on your 60A 240V WC would make me worried you electrician "cut some corners" on your installation which may not be to electrical code. IMHO I would get it inspected by your local building department not only for your safety, but IF you have a fire to make sure your property insurer doesn't deny your claim from "faulty wiring".
I pulled an electrical permit (including required load calculation) and had a licensed electrician install our daughter-in-law's new gen2 Signature Tesla WC on a 60A 240V breaker 2 feet away (8 foot wire run) for their M3 LR in their 2019 built home. Worked perfectly the moment it was connected, passed electrical inspection, and has worked flawlessly ever since. Note ALL the copper wire was completely enclosed in METAL conduit... not flex like yours and in continuous (not spliced) wires... which makes me wonder if your electrician's installation is "to code". I strongly suggest you get it inspected to verify if it is... not take your electrical contractor's word for it.
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