Hello,
Thank you for contacting Rank Math today.
a). The indexed but not submitted in sitemap error is arising from the fact that not all your links have been added. I have taken a look at your sitemap but there are only about 700 links. To fix this, please:
1. Head over to WordPress Dashboard > Settings > Permalinks
Hit the save button once.
2. Go to WordPress Dashboard > Rank Math > Sitemap Settings
Hit the save button once.
Head over to https://yourdomain.com/sitemap_index.xml and check if the number of links will have increased under each sitemap.
b). Reduction in Submitted and indexed could suggest that the frequency in which Rank Math is updating links on the sitemap might be getting hindered. Please check whether you have an exception for the sitemap file on your caching rules. The sitemap should never be cached.
c). Excluded by noindex tag Could you please share about three links affected by this problem so that we can check this further?
d). Page with redirect Kindly also share a few links affected by this so that we can check this further.
If it doesn’t, please do let us know so we can look at this further.