I am a NOOB and am struggling with similar SVG sizing issues using EleksCAM V3.1
I am using an EleksMaker Mana SE controller V3.2 and a home made Acro Laser Engraver.
You don't say what engraver you are using or what SVG generation software you are using.
I found that the SVG files I greated were burning .8 times the original size and it took me a while before it dawned on me that my Acro build uses 16 tooth GT2 pulleys on the stepper motors and the next most common size is 20 tooth... 1.25 times 16 is 20! Bingo. So I used PUTTY to connect to my COM port that the EleksMaker Mana SE board was connected to (COM6 in my case) at the default baud rate 115200 and issued the $$ command once connected and saw $100 through $102 (X,Y,Z steps per mm) set to 80 and issued the $100=100 $101=100 $102=100 commands to set those to 100 steps per mm and that resolved the basic size issue. Your issue sounds like an opposite... the steps per mm set too large for the pulley size, i.e. set to 100 and you have 20T pulleys. Just a guess.
That said, I still have MAJOR issues with Inkscape images saved as SVG and brought into EleksCAM using PicCarve function. (I believe there is a way to have Inkscape generate the Gcode and that may solve things but PicCarve should do this...)
For originals I create in Inkscape I have few issues. The key I found is to use the File>>Document Properties option to set the size of the document to exactly what I want my engraving size to be then work in that space. When I bringthose SVG files into EleksCAM with PicCarve they work well assuming I remember to set the Speed to 1000 as they come in with speed set to 0. My issue stems from Inkscape creations where I import and scale other vector graphics. Things end up scaled in their original size. There has to be a better solution than I have found, which is turn the imported object into all its objects, copy, paste into my original. Then it sizes as desired. Kluge... NOOB move... but it works.