Northerners don't eat snakes. First, they think snakes are filthy and eating them is a shame. Another idea is that snakes are spiritual and will attack people with mountain torrents and mudslides, so avoiding them will not cause harm.
It doesn't seem to have much to do with "bad luck", but someone will still pay attention. For example, snakes under the table were not eaten in the past. Reason: It may be an ancestor or a god. This may be the root of your problem.
In addition, some sayings also point out that hibernating snakes can't eat, which is too harmful to the harmony between heaven and earth (probably because snakes sleep well and don't disturb their sleep, so it is immoral to kill and eat)