I can still reproduce this now on my T470 with fully up-to-date bionic (also tried the https://launchpad.net/~canonical-x/+archive/ubuntu/x-staging PPA)

kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE)
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) Backtrace:
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 0: /usr/bin/Xwayland (xorg_backtrace+0x4d) [0x561ba663e6bd]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 1: /usr/bin/Xwayland (0x561ba6496000+0x1ac459) [0x561ba6642459]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 2: /lib/x86_64-linux-gnu/libpthread.so.0 (0x7ff68662b000+0x12890) [0x7ff68663d890]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 3: /usr/lib/x86_64-linux-gnu/dri/swrast_dri.so (0x7ff67fed8000+0x24e9e3) [0x7ff6801269e3]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 4: /usr/lib/x86_64-linux-gnu/dri/swrast_dri.so (0x7ff67fed8000+0x1b3ed4) [0x7ff68008bed4]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 5: /usr/lib/x86_64-linux-gnu/dri/swrast_dri.so (0x7ff67fed8000+0x144c6a) [0x7ff68001cc6a]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 6: /usr/lib/x86_64-linux-gnu/dri/swrast_dri.so (0x7ff67fed8000+0x144cae) [0x7ff68001ccae]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 7: /usr/lib/x86_64-linux-gnu/dri/swrast_dri.so (0x7ff67fed8000+0x144d1c) [0x7ff68001cd1c]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 8: /usr/lib/x86_64-linux-gnu/dri/swrast_dri.so (0x7ff67fed8000+0xad4b2) [0x7ff67ff854b2]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 9: /usr/lib/x86_64-linux-gnu/dri/swrast_dri.so (0x7ff67fed8000+0x25b6db) [0x7ff6801336db]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 10: /usr/lib/x86_64-linux-gnu/dri/swrast_dri.so (0x7ff67fed8000+0x3e2ae5) [0x7ff6802baae5]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 11: /usr/lib/x86_64-linux-gnu/dri/swrast_dri.so (0x7ff67fed8000+0x3e1a13) [0x7ff6802b9a13]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 12: /usr/bin/Xwayland (0x561ba6496000+0xc8989) [0x561ba655e989]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 13: /usr/bin/Xwayland (0x561ba6496000+0xc7975) [0x561ba655d975]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 14: /usr/bin/Xwayland (0x561ba6496000+0x1969f2) [0x561ba662c9f2]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 15: /usr/bin/Xwayland (0x561ba6496000+0xcc5f7) [0x561ba65625f7]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 16: /usr/bin/Xwayland (0x561ba6496000+0xc7c3c) [0x561ba655dc3c]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 17: /usr/bin/Xwayland (0x561ba6496000+0x171ec8) [0x561ba6607ec8]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 18: /usr/bin/Xwayland (0x561ba6496000+0x175f10) [0x561ba660bf10]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 19: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xe7) [0x7ff68625bb97]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) 20: /usr/bin/Xwayland (_start+0x2a) [0x561ba64d0ada]
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE)
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) Segmentation fault at address 0x68
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE)
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: Fatal server error:
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE) Caught signal 11 (Segmentation fault). Server aborting
kwi 24 18:34:27 t470 org.gnome.Shell.desktop[6195]: (EE)


Let me know if you need some interactive debugging on this.