I've upgraded everything today: wordpress, simple press plugins and themes.

So far so good, but one thing I've noticed is that I've lost the page title on each topic, it displays the url instead

Hi - are you taking about your WordPress Theme page titles or your Simple:Press theme? If Simple:Press theme, is it a standard Simple:Press theme or a customized theme. If a standard theme which one is it?

Thanks

PS: A screen shot would be helpful as well.

I'm talking about Simple:Press theme pages (reboot child theme) and the title shown in the browser tab

View post on imgur.com

I'm also using the Yoast SEO plugin

My SEO config

View post on imgur.com

Have you checked/changed/upgraded your WordPress theme? This can often be the cause of unexpected instances like this.

SP can attempt to set the page and browser heading but it is often the case that the WP theme determinedly does its own thing and overrides the title. You could test this by swapping your WP theme temporarily for one of the WP default themes to see if it corrects the issue.

SP itself does not make any attempt to output the URL so it has to be a knock on effect of another component.

No, but I upgraded the Wordpress itself and a few other plugins (Yoast being one of them)

I've switched for a moment to the Default Wordpress theme and showed the title

Algo, it looks like it sets the right title and then changes it to the url, you can see it in https://www.subnoise.es/foro/

Anything else I can try? Thanks

Hi:

Unfortunately there is very little we can when another theme/plugin sets a title.  While multiple plugins (or the theme) can attempt to set a page title ultimately only one can win.

Thanks.

I've spoken with the theme authors, they say there is a conflict between the forum plugin and the bootstrap framework

It's actually a known conflicr between Bootstrap and WP... Well, the jQuery UI library that WP uses... Themes that load Bootstrap need to.make sure they are loaded in the proper order or conflicts arise  Since WP does not itself use Bootstrap on the front end but allows it, conflict only arise when it's used by plugins.. 

If you search this forum you will find multiple topics walking through how to adjust the wp theme... We cannot do it at plugin level...