Redirects not consistently working from Google, causing indexing issue

Site URL: https://www.joshuapearl.com/

I set up redirects in Squarespace to funnel the traffic from the previous site's pages (different owner, structure, content) to that of my new site. However, if you search "site:joshuapearl.com" in Google, you will find that the redirects only work 1/2 the time. Other times, a 404 error appears.

How can I fix this, or is it a Squarespace glitch? It is making it impossible to get my new site indexed. 

URL Mapping attached.

Thank you!