Does the read receipt feature on Iphone glitch sometimes?

My question is: Are read receipts truly accurate or do they glitch up often with others as well? ( I do realize my trust issues are horrible and I might not be in a place to be in a relationship still. Which is why I'm reconsidering if I should remain in the one I'm currently invested in to heal, to give my boyfriend some time to reevaluate if it is really me he wants to be with, as I can imagine how much it hurts to love someone who doesn't have your full trust.)

Read more: https://iphoneus.org/faq/does-the-read-receipt-feature-on-iphone-glitch.html