I lost the bullets in the sidebar lists

So it probably isnt a css thing.

Its very much a CSS thing, especially since you mentioned them missing in the default theme. ? is added by the default theme’s style.css.

If you do not see them in the default theme you have either edited the style.css OR you have changed the structure of the sidebar significantly enough that you need to adjust the CSS to reflect the changes you made to the structure.

Your current theme isnt valid.

https://validator.w3.org/check?uri=https://www.fractalbit.gr/

and a good deal of the errors reside in your sidebar — so Im not going to look any further, Im sorry.

I havent messed up with the default theme at all. All the changes i made were to a custom theme. Even when i choose the default or the classic theme and remove all the widgets from the sidebar but the categories (or the blogroll, just to have something to see the lists) the bullets do not show ??

I tried with the default theme the validator you suggest and it says it passed with no errors, but still the damn bullets do not show!

If you put your site up with the default theme, I will look. Like I said though, you need to fix the validation errors on your current theme before Ill even look at that one.

Ok, I FOUND IT!!!!!!!!!!!!

The problem was caused when enabling the (excellent, except this) wp-polls plugin! No matter if a poll was enabled in the sidebar or not.

This was because, when the plugin was enabled it linked to the polls-css.css which had the following code inside:

.wp-polls ul li:before, wp-polls-ul li, .wp-polls-ans ul li:before, #sidebar ul ul li:before {
	content: '';
}

The “solution” is to remove , #sidebar ul ul li:before from the code. So you should have:

.wp-polls ul li:before, wp-polls-ul li, .wp-polls-ans ul li:before {
	content: '';
}

This will have the side effect to also show the bullet points for the poll options. I am not so proficient in css to solve this but I will inform the creator of wp-polls plugin … hope this helps someone ??