Site Maintenance Notes Unable to Save

I’ve tried this on a clean install of WordPress with no other plugins installed and a default Twenty Twenty Two theme.
WordPress 6.1
WP Client Reports 1.0.15
WP Client Reports Pro 1.0.13

When saving site maintenance notes, if select a new date and click save, there’s an endless spinning icon, it never saves and I get the error below in the console. If I don’t select a new date and click save it saves fine.

I’ve reproduced the error on latest Firefox in regular and Private windows and latest Chrome on macOS Ventura.

Please note: Developer console must be open before clicking save to catch this error:

XHRPOSThttps://stalseattle.org/school/wp-admin/admin-ajax.php
[HTTP/2 500 Internal Server Error 175ms]
	
POST
	https://stalseattle.org/school/wp-admin/admin-ajax.php
Status
500
Internal Server Error
VersionHTTP/2
Transferred721 B (178 B size)
Referrer Policystrict-origin-when-cross-origin
Request PriorityHighest

    	
    access-control-allow-credentials
    	true
    access-control-allow-origin
    	https://stalseattle.org
    cache-control
    	no-cache, must-revalidate, max-age=0
    content-length
    	178
    content-type
    	text/html; charset=UTF-8
    date
    	Fri, 04 Nov 2022 21:27:45 GMT
    expires
    	Wed, 11 Jan 1984 05:00:00 GMT
    referrer-policy
    	strict-origin-when-cross-origin
    server
    	nginx
    vary
    	X-NR-SAMPLE-PERCENT
    x-content-type-options
    	nosniff
    X-Firefox-Spdy
    	h2
    x-frame-options
    	SAMEORIGIN
    x-powered-by
    	WP Engine
    x-robots-tag
    	noindex
    	
    Accept
    	application/json, text/javascript, */*; q=0.01
    Accept-Encoding
    	gzip, deflate, br
    Accept-Language
    	en-US,en;q=0.5
    Connection
    	keep-alive
    Content-Length
    	126
    Content-Type
    	application/x-www-form-urlencoded; charset=UTF-8
    Cookie
    	_ga=GA1.2.710345251.1665087993; wp-settings-2=libraryContent%3Dbrowse%26editor%3Dtinymce%26advImgDetails%3Dshow; wp-settings-time-2=1666622557; _gid=GA1.2.2093893997.1667581799; wordpress_test_cookie=WP%20Cookie%20check; wordpress_sec_d7659e26ca9a4f2df5b02a178d950fa0=stalphonsus%7C1667754605%7CqebTXgpJcYRnWa1lpujFg56A8GQLOHQVcL3VzzPi1FT%7Cbe054031caaeb460354e2a823b18adbec95f9a2334d11a69b67ce3d7f7827798; wordpress_logged_in_d7659e26ca9a4f2df5b02a178d950fa0=stalphonsus%7C1667754605%7CqebTXgpJcYRnWa1lpujFg56A8GQLOHQVcL3VzzPi1FT%7C6c9ce17e58a80fd73a207f36d46ef71205e85e6e6f02cab714029c1231401baf; wpe-auth=65dd55548ddbcf85fa6628d48347a592ebdd502dabfdbfd9c1e3e10e7a84edf6; wp-health-check-disable-plugins=0b3a36cb15b6bef8772382ab0cb48ff3
    Host
    	stalseattle.org
    Origin
    	https://stalseattle.org
    Referer
    	https://stalseattle.org/school/wp-admin/index.php?page=wp_client_reports
    Sec-Fetch-Dest
    	empty
    Sec-Fetch-Mode
    	cors
    Sec-Fetch-Site
    	same-origin
    TE
    	trailers
    User-Agent
    	Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:106.0) Gecko/20100101 Firefox/106.0
    X-Requested-With
    	XMLHttpRequest