Unable to throw canisters with no secondary equipped during Exploiter Orb fight

[PerfectedLotus]

I've checked and no other threads on this topic appear to exist - apologies if this is a known issue, or if there's a solution I'm somehow missing.

Last night I fought the Exploiter Orb solo, bringing Nezha, a Fulmin, a Tatsu, but with no secondary weapon equipped. I discovered fairly quickly that while I could pick up thermia canisters (switching my current weapon to the Tatsu) and drop them by changing back to the Fulmin (either by aiming or pressing F), there didn't seem to be a way to actually throw the canister. Pressing the middle mouse button while I was holding a canister would instead bring the Fulmin back as my active weapon and toggle between its firing modes, dropping the canister in the process. Likewise, pressing the right mouse button caused me to drop the canister and aim with the Fulmin.

I don't believe that I've rebound any keys that would have any impact on this action - the only rebinding I know of is moving crouch toggle to the C key. (At the moment, I can't verify this, but at some later point I intend to try to replicate the issue, and at that point I'll provide either verification or correction on this point.) I was eventually able to complete the fight by using the Operator to throw canisters, but my guess is that isn't a satisfactory solution (especially considering that, as far as I know, there's nothing stopping a player who hasn't unlocked Transference from starting this fight).