That's very likely. As far as I remember, even if you select "Close channel" instead of "Force-close channel", you won't be able to specify your own transaction fee. I believe that a cooperative close (the first option) should use a much lower fee, but I am not that familiar with Electrum implementation of the Lightning Network so don't take my words for granted

I have just found a similar case to yours on the Internet. It seems you are not the only person who had a problem with this node.