I did a test with fully exposed small strip from the same Acros film, developed in the Rodinal, same result : b.l.a.n.k. clear cellulose.
Then I developed another Acros from the same batch that was still in the camera body when my baggage went thru the airport scanner. This time I use D76, same long ass stop bath and fixing time because I am still lazy. It worked. I also sent another roll that was outside the camera body to a professional lab just to rule out x-ray scanner issue.
The Rodinal I use is Adox and the last time I used it was probably a year ago or so. I definitely would not now of gradual fading that happened within the last one year.