itamarbdor issue kind of different. i still not very sure what issue with itamarbdor case. but i think some of plugin causing this issue. because when i access this page : https://ashoova.co.il/?ajax-request=jnews
the response result is 403. 403 mean forbiden access.
its meaning that the request not even reach the code. or if its reach the code, its terminated on some place.
it can be caused by .htaccess setting (if you using apache), or plugin that prevent ajax request.
may i know what server you using? also how you setup your permalink?
also what plugin you currently using?