Beacon + Spannsysteme X-Gantry = Sensing Artifacts?

Hi, I have installed the Beacon surface scanner to my printer yesterday and found a weird issue. The bed mesh has a pattern, that repeats along the Y-axis (see the first image). The hills and valleys are spaced with approximately 40mm distance. Due to the fact that the pattern stays the same, it must come from the X-gantry. I tried loosening and retensioning the linear rail while heatsoaked, to no avail (I might have now introduced some slight bend during this). As a important note, I am also using this lightweight X-gantry: https://spannsysteme.shop/produkte/x-gantry-422mm-for-ratrig-v-core. I remounted the SuperPinda today and ran a 14x7 mesh, where imho the pattern should already become visible. However there is none, which leads me to the conclusion that there might be an interference with the X-gantry. Please ignore the other bowing in the mesh for now. Maybe the pockets in the material introduce artifacts into the beacon's coil? 🤔 However the pattern doesn't fully match the pockets, as it's not fully symmetric. Is anyone using a similar setup or has any ideas? Did I miss steps while setting up the Beacon?

Spannsysteme - für die optimale Zerspanung

X-Gantry 422mm for RatRig V-Core 300 - Spannsysteme - für die optim...

Dimensions: 422 x 20 x 20 mm Weight: 86 g (vs. 194 g of original 2020 extrusion) System: Suitable for the RatRig V-Core 300 Material: EN AW 6060 T66 Production: Precision CNC milling Surface : (with minimal handling scratches) Raw aluminium Anodized black aluminium (batch 2) Note: Mounting of the linear rail with M3x8mm screws (no...