This is the same issue than
LPS-45613 but only reproduced for "Basic Web Content" for 6.2.x. and 6.1.x.
At master, the structure for "Basic Web Content" is a standard DDMStructure that exists at database.
At 6.2.x and 6.1.x, "Basic Web Content" does not exists at database and a especial logic is executed for this case, so some additional fixes must be done at that branches.
Steps to Reproduce
LPS-56443 but use "Basic Web Content" at Firefox.
Note: This issue with "Basic Web Content" is difficult to reproduce, in order to be able to reproduce easily, use Firefox and click continuosly on "Save as Draft" during 30 seconds, after a while, CKEditor content will be lost.
Additional note: at master there is another bug at this functionality (
LPS-56443) but it is a regression caused by other LPS, so it is an unrelated issue.