TTS wrong/correct pronunciation at each generation

,

When I click the generate button on playground /TTS or API with the following text. “I love books. I read then a lot.”

One time it generates “read” pronounced as “reed” the correct form, but the next time it generates “read” pronounced as “red” like in the past tense.

Some times it generates the correct/incorrect version a few times in a row.

Any idea how to fix that?

Thanks