SGA - If you unbind your primary click (left click) button in G Hub and are running Windows 10, you can use mouse accessibility tools fix that.

I've been using the G-Shift button function to give me some more options with my G703 mouse and unbound the primary click button on the G-Shift side of my game profile before I was done setting all of the button mappings. Once unbound, there was no way to make any other changes in the g-shift profile. After my numpad fix, I went back in and bound all of the buttons other than the primary left click and did that one last. If anyone knows of a workaround or button shortcut in G Hub that acts like a left click please comment. I haven't looked into that yet.

Without a primary click, your mouse is more or less becomes inert. You have no options to get it back without primary clicking! You can get around this without hooking up another mouse if you have access to the number pad buttons. If you have another mouse you are all set to plug it in and fix your settings. This may be complicated with a laptop or a tenkeyless keyboard but there is often a numlock / function / fn key that allows use of the number pad buttons on those devices.

If you have access to number pad buttons and unbound your primary click, you can use your keyboard hotkey Win + S to open the search dialogue in Windows 10 to work on a fix for that. After Win+S, just type in "ease of access mouse" and you should be able to arrow down or up to that built in Windows 10 accessibility app and press enter to open it. When your in, press the space bar to enable it. The 5 on your number pad acts as a primary click so you can navigate back to G Hub with your mouse and the 5 button to bind something to primary click. Afterwards go back into the accessibility settings and disable the keypad functions.

I'm sure there are other ways around this but I was in game and in a jam testing out the G-Shift button and even though I had a mouse right here next to me, didn't think about that until afterwards...

I'm sure some smart folks can elaborate on what options are available if you are on a laptop or are using a TKL keyboard in the comments.

TL:DR - don't unbind your primary click in G HUB, if so scroll up and try my method.

After typing this, I kinda feel like throwing in my experiences with the Logitech G devices and software. So far I'm really happy with my G815 keyboard (clicky) and G703 mouse. I upgraded from a Corsair STRAFE RGB (MX Silent) and a Razer Deathadder Chroma (R021-0121 series). The lower profile clicky keys aren't too loud and just feel a lot better for daily work / typing than the MX Silent with Corsair keycaps. I'm not miss handling movements in games as I hear / feel the clicks and just have a better feel for the keyboard with the feedback I'm getting, so that is a bonus. I was concerned about a new mouse as I've been using the Razer for years and it just felt good. Well the G703 feels better in my hands. There was absolutely nothing wrong with the Razer, I just got tired of the problems with the Razer app and how it randomly asked for a log in to their cloud service. Without the Razer app running my mouse reverted to defaults. Now I've dumped the I-CUE and Razer app from my PC and am having good results with the G Hub app to control both the mouse and keyboard. G Hub will operate locally with no added accounts but I probably need to backup or sync my stuff to the cloud so if my PC goes south I won't have to recreate all the mouse and key binds. - Derp