can menstrual cups cause inflammation

i have been using menstrual cups for 7-8yrs, but in recent cycles i am facing an issue. May be or may not be it is related to menstrual cup.
After i remove my cup at the end of the cycle, even after 2-3 days if i get into sex my vulva pains like burning. the pain happens to be so intense that i sometimes shout. but after 5-6 days, its gone.
i do lubricate it every time i insert.
one thing to note is, i purchased new cup 7 months ago and getting this problem nearly since 5-6 months.