This is not a problem. This is a necessity to protect you from workflow interruptions. Owing to Adobe's new version policy, we no longer have access to pre-2019 versions unless we kept them installed on our computer. Once they are uninstalled, they disappear from Creative Cloud desktop app.
You don't have to be a computer genius to use Creative Cloud. But at a bare minimum you must be responsible and exercise some common sense.
Don't upgrade during major projects. Defer that for when you have some free time to learn new software.
Always maintain reliable backup copies of important work files.
Always keep the previous software version installed just in case the new one doesn't work out. When you are quite certain you will never ever need the previous version, uninstall it.