Hard to Shift Into Gear, Can't Shift Into Low

[Macleod52]

I have a 2017 Sierra SLT 6-spd with 55k miles. Today I started having difficulties selecting gears and I cannot shift into low gear. Has anyone experienced this before? Could this be a shifter cable issue or something else? 

Edited April 15, 2021 by Macleod52

[Macleod52]

So the issue was the lower shifter cable that is attached to the transmission was pretty rusted and was causing the issues. The boot looked to be in good condition so I don't know how moisture got in. Anyway I took some emery paper to it to get rid of the rust and put a layer of lithium grease on it to help prevent it from rusting. A friend recommended using some Anti-Seize lubricant instead so I will be doing that as It should be a longer lasting option.