Hi @krzysogi , could you try deleting your alert via Favorites (as @JimInSanDiego suggests) or directly via the email (the clickable last line "Edit / Unsubscribe this alert"). Both ways are working for me.
If it doesn't work for you, please send us the ID of the alert(s) that are concerned. You will find it in the URL when you're on Windy.com –> the particular alert –> copy and paste the URL. Also please give us info about your OS, device, browser / app version... Thank you.