Well, I don't want to blame you, but you have or had barely any knowledge about how Lighning works.

The screenshot you showed: ~40sat/vB was the minimum fee that got into the blocks

My Electrum (desktop) asks me to specify the transaction fee and I have choices and a fee slider, don't you had it? I can choose more time for confirmation of the on-chain transaction to open the channel and thus a lower fee level. Maybe Electrum's default is to choose a higher priority of confirmation than to save fees. How good is your knowledge about optimal fee choice based on current mempool state?

I would've chosen something like 60sat/vB for May 11th (not sure if you tried on that day, May 6th 'til 10th had higher ridiculous fee levels), why haven't you? Why had you Electrum stick to 500sat/vB fee as that's likely the high priority fee choice (confirm in next one or two blocks)?
Could it be, you used the mobile app and there maybe fee selection is hidden first or needs to be activated? I played around a little with mobile Electrum but never seriously used it as I won't use a mobile BTC wallet with more than pocket money amounts.