Previous Posts Not working – Permalink Issue

I am running 2.7.1 on IIS. The site is working with permalinks only when I use ?p=xxx format or /index.php/%postname%/ format.

I currently have my permalink set to /index.php/%category%/%year%/%monthnum%/%postname%/

When I am on my home page https://www.bhargavs.com, At the bottom of the page, I have “<< Older Entries” which when I click lands on a blank page. When I checked the link for it, it is https://www.bhargavs.com/index.php/Index.php/page/2/. Not an extra Index.php in the link.

I have tried default theme and other themes but issue remains. The only way I was able to get this to work was change the permalinks to /?p=xxx which isn’t an option for me.

Can someone help me fix this? How can I fix it so that it does not add extra index.php in the link?