Can't switch template of existing page

[dlen]

When I create a new page, i can choose between a couple of templates.

but after creation, when i go to the - settings/template dropdown, there is only one template to choose from:

The respective template setting is in default, i.e. allows to change the template. 

Any hints welcome!

[BillH]

You might find an answer in this discussion, which covers all the possibilities I could think of - and a couple more!

 

[dlen]

Many thx. Wouldn't have thought so, but downgrading PHP to 7.4 fixed the problem.