Rules for writers, Tenth edition - Diana Hacker, Nancy Sommers 2021

Make the verb agree with its subject even when the subject follows the verb
Make subjects and verbs agree
Grammar

Verbs ordinarily follow subjects. When this order is reversed, it is easy to become confused. Sentences beginning with there is or there are (or there was or there were) are inverted; the subject follows the verb.

Occasionally, you may decide to invert a sentence for variety or effect. When you do so, check to make sure that your subject and verb agree.