Strange when a spread is not aligned. Pages are the same format.
Is there a hidden feature?
You appear to have set up a bleed or slug on the left hand page and not on the right hand page – check your setup.
(probably the page has been moved accidentally)
with "page tool" select the left page and set "y" reference point to 0
You should set up your document as document with facing pages as it has facing pages, this will align the pages. There is no reason, if a document has facing pages not to set it up that way.
Worked like a charm on Adobe indesign 2020. Thank you so much!