No validator could be found for constraint 'jakarta.validation.constraints.Pattern' - error still appearing even after deleting validator from class

I have used @Pattern to validate text input for a long time in my project and never had an issue. All of a sudden I'm getting the following error:

jakarta.validation.UnexpectedTypeException: HV000030: No validator could be found for constraint 'jakarta.validation.constraints.Pattern' validating type 'com.helpmesaythis.hmst3.profile.promo.model.entity.DiscountPromoCode'. Check configuration for 'discountPromoCode'

There are two strange things at play:

There are other classes using it without an issue and I haven't even touched this problematic class in a long time (it has always worked).

I have tried commenting out and even deleting it entirely from the class, yet the error still appears. How is it causing an issue when it doesn't even exist?

import com.helpmesaythis.hmst3.profile.partner.model.entity.Partner; 
import jakarta.persistence.*; 
import jakarta.validation.constraints.Pattern; 

@Entity 
@Table(name = "discount_promo_code") 
public class DiscountPromoCode { 
    ... 
    @Size(min = 4, max = 20, message = "Promo Code must be between 4-20 characters") 
    @Pattern(regexp = "[A-Za-z0-9]+$", message = "Promo Code can contain only letters and numbers") 
    @Column(name = "promo_code") 
    private String promoCode; 
    ... 
}

I have made sure that all dependencies are up to date. My Spring Boot is up to date.

Again - the @Pattern annotation works everywhere else, yet I get the same error message even after it has been deleted from the problematic class.

When I include spring.jpa.properties.javax.persistence.validation.mode=none everything works as it should.

Any ideas?

As andrewJames pointed out in the comments, the error was coming from the field discountPromoCode and not the class DiscountPromoCode. The error itself was because I was using @Pattern to validate a field that was not a String.