Looks like a training issue. The main issue appears to be related to your detector settings. Please select DAD wavelength values that are appropriate for use with your method. IOW: TURN THE REFERENCE WAVELENGTH software 'OFF'.
Here are links to several free articles which may help you.
"
Common Causes of Baseline Noise in HPLC, UHPLC";
https://hplctips.blogspot.com/2014/09/c ... noise.html"
REFERENCE WAVELENGTHS (as used in HPLC UV/VIS)";
https://hplctips.blogspot.com/2011/03/r ... -hplc.html"
Proper Wavelength Selection for HPLC Method Development (or Purity Determination)";
https://hplctips.blogspot.com/2013/08/w ... ethod.html Additionally, please make sure you are controlling temperature well before using the system. Even a small temperature difference (i.e. 1 C) may result in drift or noise. Please allow enough time for complete equilibration of the column and system before starting an analysis. This is aided by continuous degassing of the mobile phase to prevent pump instability, use of fresh solvent pickup filters and making sure you properly prime all channels with fresh mobile phase before use. Lastly, once everything is clean and the detector settings are changed, please run a detector lamp intensity test (follow the instructions in the software) to confirm the lamp has plenty of output in all ranges used and passes the compliance tests.