Be careful mixing greases.
I was in the machine tool industry for over 40 years and learned a lot about grease and oil. Some of what I learned, I learned the hard way.
All greases are not COMPATIBLE. Grease is made of three components, Oil, Base Carrier, and Thickener. The oil in grease is actually the component that provides the lubrication. The Base Carrier holds the oil together so it does run, sort of like a sponge. The Thickener does just what it says, it gives the grease a particular composition and tack.
If you mix two greases, one of three things occurs:
1. Nothing, everything is compatible and life goes on.
2. The carriers react together and dissolve, leaving the oil to run out the components it was lubricating. Eventually the moving machine components dry up, make noise, and seize.
3. The carriers react together and dry up, turning into a dry powder, similar to fine sand. This is the worst and causes the most damage. The mechanical components must be taken apart and totally cleaned or replaced.
If you do not know if the new grease is compatible with the existing grease, you should clean out the old grease and purge the fittings and lines. Then make a of note of the new grease and stick with it.
There are several documents on the internet verifying what I just stated. Many are at the engineering level. The easiest to understand is by "Bob is the Oil Guy." Pay close attention to the last couple of sentences. Here's the link:
https://bobistheoilguy.com/forums/threads/grease-compatibility-chart-and-info.319785/