Hi.
Not SPPB bug, but I publish it here because I do not have JCE subscription. Perhaps @Paul Frankowski will look here and will be able to report the problem to the JCE developer.
J4, SPPB 3.8.9, JCE 2.9.33 (Core).
Being in the SPPB frontend editor , buttons Editor, Code, Preview of JCE editor do not switch the corresponding tabs in JCE, but switch the General, Style, Advanced tabs of SPPB.
Return to the JCE 2.9.32 (Core) eliminates the problem.