Canon R7 wi/RF 100-500 keeps changing shutter speed while in Manual

[mikellherrick]

I've been noticing that while shooting (often in low light) my R7 will automatically change my shutter speed to 1/125 even though I have manually selected 1/400 typically. ISO is always on Auto and aperture at widest allowed for conditions.  Is that normal?  Is it because the camera thinks I can't get a good shot shooting that fast?  If I move my frame around a bit...or reset the manual speed back to 1/400...it will usually allow me to use that speed.  It is annoying because I'm also shooting in continuous mode (mechanical) and find I'm getting overexposed or blurred images when this happens. 

[shadowsports]

Greetings,

I suggest you follow Waddizzle's reset recommendation.  We do see an above average number of "unexplainable behavior" that get corrected with settings reset.  Hopefully this will resolve your issue.