Hope you are doing well and sorry to hear that. As described, when you edit the numbers in the PDF file and save it, it save some random numbers.
I have checked the Adobe Account linked with the Adobe ID you are using on this community and found that you have Acrobat Pro DC (Paid Subscription). Please confirm if you are using Acrobat Reader (Freeware) or Acrobat Pro DC (paid subscription).
If you are using Acrobat pro DC, what is the version of the application you are using? To check the version go to Help > About Acrobat and make sure you have the recent version 21.11.20039 installed. Go to Help > Check for updates and reboot the computer once.
Also is this a behavior with a particular PDF file or with all the PDFs? Please try with a different PDF file and check. If the file is stored on a shared network/drive, please download it to your computer locally and try again.