I am a biologist and am forced to use .svg files to compile larger figures of a paper but I don't manage to do what I want despite days of trials. I must add I have no knowledge about graphics unfortunately. So please forgive me if my wording is not very accurate
Here is the project. I have two DNA regions with arrows representing genes in these areas. The two DNA regions have been drawn in a software called sequence viewer and each exported as an .svg file. When I open each file individually, no problem, I can edit then as I wish but I need to create a file that has the two sequences inside the same image and I don't manage to "fuse" the two files.
If I open file 1 and then drop file 2 inside file 1, some colours are distorted, some items do not appear and worse, as soon as I degroup the image from file 1, image from file 2 disappears, at least partially ! This problem persists even if I create a second layer (Calque in French) to drop the second file. Similar problems arise if I open file 2 and rop file 1 or if I open a blank file and drop the two files inside.
I have no idea what else to try because I realize what I am trying to do should be extremely easy

Thanks for reading me and I hope you can help me. Don't hesitate to ask if something is not clear and i'll try to explain better.