Truecaller reads new SMS sometimes even without having SMS permission

I use Redmi 9 Prime. On that, I use the Truecaller app. I want to use Truecaller only for calls and strictly not for SMS. So I never give SMS read permission to the Treucaller app. But still, sometimes Truecaller read new personal SMS. Till now did not see any service or OTP SMS in Truecaller. Don't know how come. What can be the reason or source for getting this possible? How can I stop Truecaller from strictly touching my SMS?