We also faced same issue in one of our instance where accounting users were unable to post the payments due to this User Error! We figured out the issue and here's the solution listed below with exact mention of the issue.

What happened

• A recent Odoo 17 core change added a stricter company-consistency check on journal entries.
• That change was rolled into the latest Odoo.sh base image, so many projects started seeing the error:
  “The entry is using accounts from a different company.”

Current status

• Odoo has reverted the change upstream.
• The Odoo.sh base image hasn’t picked up the revert yet; it will be included with the next weekly refresh (Odoo.sh usually updates the core on Mondays).

Immediate workaround (Odoo.sh)

Pin your project to a known-good revision until the new image lands:

1. Go to Staging/Production → Settings → Odoo Version → Revision
2. Set the revision to 17.0.20251103
3. Save

This restores the previous behavior and removes the blocking error.

After the Odoo.sh refresh

• Once the new base image with the revert is available, you can switch your project back to Latest (or unpin the revision).

Side note

• Regardless of this temporary issue, the safest long-term setup is to keep journal default accounts and all used accounts in the same company (or its children) to avoid future validation errors as Odoo tightens multi-company rules.

Just did check the accounts, journals, product categories, taxes, and customer/vendor configurations all are the same. Yet I still get the error, also checked the company assignments are the same also are error.