General Journals - stop auto removing Description when the Account Type is changed
You can use the hidden Keep Description field. Not sure how you import the general journal, but try to import the Keep Description = true as well. That will preserve the description.
I also have the free app below that you can download to expose the Keep Description on the page.
General Journals - stop auto removing Description when the Account Type is changed
not sure how you import the entries, but if your excel is integrated with BC, you are able to populate all your fields correctly there, then publish back to BC. this way, you won't worry about the changing fields.
this is officially called Business Central Add-in for Excel
General Journals - stop auto removing Description when the Account Type is changed
Not out-of-the-box, as there is Validation on the No. field in Journals. You'll need to write an Extension to preserve the existing Description when a No. is changed. You may want to consider a prompt as to whether to change the description, as sometimes you may make a change and want the Description to use the Default Description for the new No. Expanding that a bit, you could make it User specific by adding a Boolean in the User Setup to control whether the Description changes based on the User making the entries.