Why is Cleanmymac no longer working? What other app do you recommend?

First, there is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus, VPN or security apps on your Mac.  This documents describe what you need to know and do in order to protect your Mac: Effective defenses against malware and other threats - Apple Community and Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support.  

There are no known viruses, i.e. self propagating, for Macs.  There are, however, adware and malware which require the user to install although unwittingly most of the time thru sneaky links, etc.   

Anti Virus developers try to group all types as viruses into their ad campaigns of fear.  They do a poor job of the detecting and isolating the adware and malware.  Since there are no viruses these apps use up a lot of system resources searching for what is non-existent and adversely affect system and app performance.

There is one app, Malwarebytes, which was developed by a long time contributor to these forums and a highly respected member of the computer security community, that is designed solely to seek out adware and known malware and remove it.  The free version is more than adequate for most users.  

CleanMyMac is considered to be akin to malware by most of the experienced contributors to these forums. Uninstall it according to the developer's instructions. You'll notice that all responses to your initial post are in total agreement on this.

i use etrecheck and malware bytes the free version and scan every now and then

these forums are full of people wanting to get help uninstalling cleanmymac and such apps that have made their macs a mess and seems to be difficult to get rid of

Clean my Mac is complete garbage. ALL so-called cleaning apps should be avoided at all costs. They will do nothing but cause you grief and pain.

Etrecheck is not a ‘cleaning’ app. It is a diagnostic utility written by a high level member here designed to gather information for troubleshooting. Etrecheck is fine. malwarebytes can also be useful.

+1 to both previous replies.

if you want to see what can happen if you use CMM (or other such apps as well) please have a look at the question posted here > CleaMyMac - Apple Community

See this excellent article written by a respected forum contributor for keeping your computer and yourself safe:

Effective defenses against malware and other threats - Apple Community