Upfront CPU Spike to 100%

Upfront is loading slowly, when monitoring the server performance using htop command, I can immediately see the CPU usage spikes to 100%, when Upfront is opened for posts, and custom post types created via CPT UI plugin. Was able to notice the following error in the console for the CPT pages created.

Uncaught TypeError: Modernizr.mq is not a function
at eval (eval at <anonymous> (jquery.js?ver=1.12.4:2), <anonymous>:334:14)
at eval (eval at <anonymous> (jquery.js?ver=1.12.4:2), <anonymous>:317:429)
at dispatch (jquery.js?ver=1.12.4:3)
at r.handle (jquery.js?ver=1.12.4:3)
at Object.trigger (jquery.js?ver=1.12.4:3)
at Object.a.event.trigger (jquery-migrate.min.js?ver=1.4.1:2)
at jquery.js?ver=1.12.4:3
at Function.each (jquery.js?ver=1.12.4:2)
at a.fn.init.each (jquery.js?ver=1.12.4:2)
at a.fn.init.trigger (jquery.js?ver=1.12.4:3)