Why cant i follow my friend on instagram?

[Nicholas Villanueva]

everytime i click follow it says "following" for a second then automatically unfollows him and i keep clicking to follow him but it immediately unfollows him! i used to have him blocked for sometime but i unblocked him and he doesnt have me blocked cuz he even followed me today, i tried deleting the app and reinstalling it but didnt work and i even turned my phone off and turned it back on but still doesnt work! help please

[Matt]

sometimes that happens to me and I just log out and log in and then it works
and can you more time this

[Daniel]

Try Signing off than Back In If That Does Not Work you May Be Blocked From Following People or you may Have Reached the Following Limit