There are several things happening here. 1) You have to understand that in EasyEDA, unless you use the flip board Extension, the view point of the PCB is always looking down onto the top layer. 2) it seems that you have not understood clearly - or are not visualising correctly  - what happens when you swap a component from the top layer to the bottom  layer (or vice versa). It may help you to draw the outline of your connector with the pins numbered, on a piece of tracing paper and then turn the paper over to represent swapping ot ontobthe other and note how the pin position change depending on exactly how you turn the sheet over (I.e. if you rotate it at the same time or not). 3) Your project is private so only you can see it and you have not posted any images to illustrate your question but it seems  likelyvthstvyou have created your PCB directly in the PCB Editor without first creating a Schematic. If that is true then you may have not correctly assigned net names to the tracks and the pads so that when you swap the component from top to bottom, the connectivity does not follow the new pad locations. The procedure for correctly assigning net names for PCBs created directly in the PCB Editor is covered in the description of the Connect Pad to Pad tool on the Tutorial.

Thanks for the reply. I am new to EasyEDA as of this week. In my simple example I did create a schematic with a 2x3 pin header with PIN 1 3v and pin 2 5v. The rest are irrelevant for this purpose. When I then convert the schematic to PCB it all looks fine with the header on the top layer showing P1 (3v) lower left and P2 (5v) upper left. If I highlight it and click B to move it to the bottom layer, I still want Pin 1 to be the lower left pin and Pin 2 to be top left. i.e. as I look down on the board. As this will connect to an underlying female pin header. However, it flips the header, so the pins are reversed and I fully understand why it does that as everything has been transposed 180 degrees but I do not want that and don't know how to address it.

How about you: 1. Ignore the pin numbering; 2. Redraw the schematic so that the connections go to the correct physical pin locations when the header is fitted on the bottom layer?

That is basically what I have done. I am connecting my pin to where it should be on the bottom layer and it will suffice.. Thanks

@andyfierman This is the second thread I've found with the same question and you replying "I do not think you understand .... top down view... etc..."     Both people have worded their question quite clearly - no pictures necessary.   I do not think "you" understand what happens when you look at a header's pin 1 from top side view when you move the component to the bottom layer.

@andyfierman so.. this is the best solution for a 40 pin header?   Manually mirror each pin one by one?  - There isn't a bottom mount mirror button, or potential alternate part available?

@whitemyth, it might help if you explain why you want to do this or what you are trying to achieve by it. Then perhaps more constructive advice can be offered.

"There isn't a bottom mount mirror button" Not in EasyEDA Std. (This action is available in EasyEDA Pro: When moving the component AND press X or Y key at the same time, a dialogue box pops up and asks you if you wish to mirror the component.)

@andyfierman I am assuming @whitemyth (and others asking similar questions about bottom-mounted 40-pin components) is creating a Raspberry Pi HAT. I am working on a similar projet. These boards fit on top of a Raspberry Pi by attaching to its 2x20 male header; therefore, the HATs need a bottom-mounted female header for accurate fit. I will try the mirror feature and follow up if it does not work.