So, how to tell if a film suffers from halation? It's quite easy - just look at the edges of the film frame. Here's a few examples from random rolls of F400; literally the first two rolls I came across going through an old folder.
Note the blooming around the frame edges. Lens used was a fairly modern Canon EF lens, not particularly prone to blooming or haze, and more importantly, the fact that it crosses the frame borders rules out the lens as the culprit. Of course, halation does not only occur at the edges of the frame - it's just easily visible there.
Another one. Overcast day. Note the blooming in the center.
One more. Note how the windows basically 'extend' behind the camera's film gate. The same is visible in the frames between the windows, which suffer degraded contrast as a result
Or maybe your camera has a very reflective backing plate.
Shoot Foma 400 side by side in the same camera with something like HP5+ and note the difference.
Mind you, ALL films will suffer from halation to some extent, but Foma 400 is relatively prone to it - in fact, of the regular B&W still films I've used, it halates the most strongly. The only 35mm film I ever shot that does it more strongly is the obscure 'Polypan F' stuff that was allegedly an oddball cine duplicating film.
The severity of the effect furthermore depends strongly on shooting conditions. This explains to a large extent why some may never run into the issue, while others find it objectionable.