VPN turnes ON oft itself and allways turn off Internet

Hi, I have Avast One free version. Inside the program it is VPN Secure Connection limited to 5GB. I allways turn it off, but it very offensively turns on by itself, after reload or something else. After it is on, its allways turns off internet in my browsers when even it is still 4.99 GB awaileble. I do not want to delete antivirus, but I do not want to waste time on turning off VPN. Can you please help me or to turn off VPN for allways, or to make it work? Thanks a lot, Maria
PS I`m although ready to change Antivirus, because it stills to much time, can you advise me some free for Germany, that will protect not worser?