I acquired less than a month ago a new Macbook pro 14 M1 , prior to this I used to work with different Mac Books ( intel based ones ) connecting external monitors ( two monitors ) via docking stations . It worked pretty well. After migrating to this new Macbook I tried to use the same dock station ( Baseus 7 in 1 USB type c ) , that has two HDMI ports. To my surprise , despite having two external DELL monitors connected ( obviously each of them in each of the two HDMI ports ; both same model ) the system only recognizes one !!! I have tried whatever I could to make it work but no success , both monitors simply “mirror” each other as if I had just one external device . My way around was to unplug one of the monitors from the Baseus docking station ( wich by the way was connected to one of the 3  built in USB-c ports) , and connect it directly in the HDMI built in port in the Macbook , it worked ! I also tested using instead another USB-c port with an HDMI adapter and it also worked too ! My conclusion is that regardless how many HDMI ports one’s adapter or docking station has , if such device is connected via USB-c port , it only “reads” as if there is one single monitor plugged into it ! two use more than one external monitor ( extended ) , one has two use another port , being either USB-c or HDMI builtin directly ! ( I use Mac OS Monterey 12.0.1 ) . Hope this helps