Another somewhat similar report involving Ctrl key and artwork nudging I made 5 years ago:
Ctrl+\ hotkey for Isolation mode makes art shift left upon entering
http://illustrator.uservoice.com/forums/601447/suggestions/39179098

Confirming

Thanks for confirming Egor, I didn't think this problem would date all the way back to 2019 and probably even earlier. I would hold the Ctrl and tap the ] for the most part, but I'm trying to adapt a macro pad to my work flow, and like the Japanese user below has stated in 2021, the problem cannot really be avoiding when assigning this keystroke to a macropad and it happens more often in fact with more consistency.

Please Adobe fix this crazy interaction.

This looks cursed.
I AM able to reproduce it onw Windows 10, although it is somewhat unreliable — it indeed happens right when the releases match in time. Spamming it is indeed a simple way to trigger it.

It does not happen with the [

The step recorded in the History is actually 'Move', and judged by the distance, it is just equal to pressing → key
If I unbind the default Bring Forward hotkey form the command in Keyboard Shortcuts — it STILL triggers.

I can’t reproduce anything similar in Photoshop or InDesign.
I was not able to find general mention of something similar ever happened in other conditions in other apps.

It seems to be just a weird combination of coincident triggers.
So far I can offer a workaround and just never release Ctrl until you are done with bringing the selection forward, but I guess you know it already.
Thanks for the report. Let’s see how it goes.

A similar bug report:
Ctrl key moves canvas in Illustrator rendering Ctrl-Z unusable
http://illustrator.uservoice.com/forums/601447/suggestions/31589470

Press Ctrl + ] repeatedly back to back while selecting any object and it will move to the right, despite this shortcut function being "Send object forward". You must click Ctrl + ] at the same time without holding any buttons. Finger up and down for both keys at the same time. Do not hold Ctrl key. When done as specified it will shift the object that is selected to the right. It's some kind of bug interaction that's very cancerous. Fix please.

OS:Windows10
Illustrator v25.4.1とv26.0.1 両方で確認

JISキーボードにおいて、初期設定では｢前面に移動｣で登録されているCtrl+]キーを入力すると、稀に選択中のオブジェクトが前面に移動すると同時に右方向へずれる(→キーを入力した時と同じ)挙動をする現象を確認しました。

キーボード操作だとCtrlキーと]キーを同時に連打すると稀に起き、サードパーティ製のキー入力デバイスで"Ctrl+]"と同時入力するよう設定し機械的に入力すると、より確実に同様の現象が起きます。