Just to answer possible future stuck developers trying to forward graphics throuhg ssh:
Solution: ln -sf /usr/lib/aarch64-linux-gnu/libdrm.so.2.4.0 /usr/lib/aarch64-linux-gnu/libdrm.so.2
Answer: Somehow libdrm.so.2 is linking to /usr/lib/aarch64…/tegra/libdrm.so which doesn’t seem to have the symbol it is complaining about (drmSyncobjTimelineSignal), it shows as undefined and possible the lib it should define (if not the drm itself, seems not to be correctly linked or somehting in the likes). That symbol is well defined on libdrm.so.2.4.0.
Don’t know why or the possible effects on other applications but this solution enabled the ssh graphic forwarding.