I had the same issue then I remembered that I have made changes to page size for my main page that’s I could not make it default.
So to fix this I made my other page smaller in page size compare to my default page and then went to default page and deployed the report since then works fine for me.
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I found that the page you are on is set as the default page when the report is publish.So try this. Save a copy of the report and publish it when you are on the page that you want to be the default opening page (landing page).
Hope this works,