If the setting is not it, here is the sequence that actually separates the two. Run it in this order, because each step is cheaper than the one after it.
1. Same extension, different browser. You have already done this and it works elsewhere. That rules out the extension's logic being broken — the code that decides what to suggest is fine. It does not rule out the extension, because the part that draws an overlay on top of a page is the part most exposed to how a given browser renders things.
2. Same browser, different password manager. This is the step people skip and it is the one that carries the most information. Install any other manager with an inline-suggestion feature and try one login field. If it is also missing, the browser changed something about that surface and no extension-side fix exists. If the other one works, the fault is in the interaction between your extension and this browser, and the extension's authors can fix it without waiting for the browser.
3. Find the boundary. Note both version numbers — browser and extension — then find the last combination that worked. "It broke last Tuesday" identifies nothing on its own, because browsers and extensions both update themselves silently and often in the same week. Two things changed; only the version numbers tell you which.
That third point is where most of these threads come apart. Someone reports it started at browser version X, and it did, for them. Someone else's extension had updated the day before and they never looked. Both post the same sentence and the thread now contains two incompatible timelines that nobody can reconcile.