DKIM fail when also using SendinBlue/Brevo DKIM values

I am getting DKIM fail because I am also using sendinblue DKIM records.

Entries for DKIM mailinbox are:

mail . _domainkey

v=DKIM1; h=sha256; k=rsa; s=email; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQE*******

Entries for sendinblue are:
mail. _domainkey

My errors in gmail is like this (
ARC-Authentication-Results: i=1; mx. google .com;
dkim=fail header.i=@******ech .com header.s=mail header.b=“cl/tUbWI”;…

Authentication-Results: mx.;
dkim=fail header.i=@*****ech .com header.s=mail header.b=“cl/tUbWI”;
spf=pass ( domain of support@***ech .com …

DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=***ch .com; s=mail; t=1700909023; bh=g3zLYH4xKxcPrHOD18z9YfpQcnk/GaJedfustWU5uGs=; h=Date:From:To:Subject:From; b=cl/tUbWIWu4LFtWIYhrkZAgfArfnhX1W/BdhBFCjhmY40T47zwJ/VTkSINraXyto5
qfGg0dMXZ9K6MXhOKorNJzJo/Oo5RRT0/g31CAmm ************

When i remove sendinblue enteries in Cloudflare DNS record, DKIM error go away and mail is signed by domain appears.

So here both sendinblue and mailinbox using same names mail. _domainkey
is the error because of this???
we can change anywhere or any suggestion please, I try many things but it doesnt work.

Yes. I suggest contacting Sendinblue and asking if they have an alternative DKIM selector that you can use.

Alternatively, you can quit using MiaB or Sendinblue.

Thanks @alento I contacted Sendinblue and there they have 2048 bit hostname with different name so one has to request through support to change from mail. _domain .key to sib2k. _domain .key and now its working.

So my question now is there anyway in MiaB to change their hostname for DKIM if needs arise. From mail to some other text?

It could be done, but it would be an unsupported modification and so outside the scope of the project that I am 99.9% certain that it would never be considered for inclusion. Especially with the lack of developers the project has now.

It would have been better for future developers in case anyone would note that not to use “mail” as DKIM hostname, simply named it differently, so no change required.