@anotherearth --- That sounds like a red flag to me. I never heard of publishers doing that.

Histria Books accepts simultaneous submissions for queries or initial proposals, but if you are invited to submit a formal proposal and a completed manuscript for review by our Editorial Board, WE WILL ASK THAT IT FIRST BE WITHDRAWN FROM CONSIDERATION AT OTHER PUBLISHING HOUSES BECAUSE OF THE TIME AND EXPENSE INVOLVED IN THE FORMAL REVIEW PROCESS.

This last stipulation seems unfair. You shouldn't have to jeopardize your other submissions in order to be considered at Histria because if they reject you then you've lost your chances for all other submissions.

Query 1/19/24 Christian Sci-Fi, 84k words; with 3 chs.
Receipt ack'd by email 1/19/24 (Does everyone realize that receipt of queries can be ack'd automatically?)

7/9/2023 Sent PB Proposal
9/8/2023 Invitation to submit book

Histria Kids – an imprint dedicated to books for children and young adults that seek both to educate and to entertain. For children’s picture books, we give priority to book proposals that already have an illustrator, although occasionally we consider works for which we will engage our own illustrator.
https://histriabooks.com/submission-guidelines/