HI, I am getting a bunch of these warnings in stage 31 -

29. Executing OPT_CLEAN pass (remove unused cells and wires).
Finding unused cells or wires in module \user_project_wrapper..
Removed 16 unused cells and 690632 unused wires.
<suppressed ~129 debug messages>

30. Executing INSBUF pass (insert buffer cells for connected wires).
Added user_project_wrapper.$auto$<http://insbuf.cc:79:execute$985200|insbuf.cc:79:execute$985200>: \io_out [8] -> \design_top.LEDFF[0]
Added user_project_wrapper.$auto$<http://insbuf.cc:79:execute$985201|insbuf.cc:79:execute$985201>: \io_out [9] -> \design_top.LEDFF[1]
Added user_project_wrapper.$auto$<http://insbuf.cc:79:execute$985202|insbuf.cc:79:execute$985202>: \io_out [10] -> \design_top.LEDFF[2]
Added user_project_wrapper.$auto$<http://insbuf.cc:79:execute$985203|insbuf.cc:79:execute$985203>: \io_out [11] -> \design_top.LEDFF[3]
Added user_project_wrapper.$auto$<http://insbuf.cc:79:execute$985204|insbuf.cc:79:execute$985204>: \io_out [15] -> \design_top.GPIOFF[0]
Added user_project_wrapper.$auto$<http://insbuf.cc:79:execute$985205|insbuf.cc:79:execute$985205>: \io_out [14] -> \design_top.XTIMER                                                                                                                                                                                                                                                                      31. Executing CHECK pass (checking for obvious problems).
checking module user_project_wrapper..                                                                                                                                                                    Warning: Wire user_project_wrapper.\io_out [23] is used but has no driver.
Warning: Wire user_project_wrapper.\io_out [22] is used but has no driver.
Warning: Wire user_project_wrapper.\io_out [21] is used but has no driver.
Warning: Wire user_project_wrapper.\io_out [20] is used but has no driver.
Warning: Wire user_project_wrapper.\io_out [19] is used but has no driver.
Warning: Wire user_project_wrapper.\io_out [18] is used but has no driver.
Warning: Wire user_project_wrapper.\io_out [17] is used but has no driver.
Warning: Wire user_project_wrapper.\io_out [16] is used but has no driver.
Warning: Wire user_project_wrapper.\io_out [15] is used but has no driver.
Warning: Wire user_project_wrapper.\io_out [14] is used but has no driver.
Warning: Wire user_project_wrapper.\io_out [13] is used but has no driver.
Warning: Wire user_project_wrapper.\io_out [12] is used but has no driver.
Warning: Wire user_project_wrapper.\io_out [11] is used but has no driver.
Warning: Wire user_project_wrapper.\io_out [10] is used but has no driver.
Warning: Wire user_project_wrapper.\io_out [9] is used but has no driver.
Warning: Wire user_project_wrapper.\io_out [8] is used but has no driver.

on output ports that are driven. Some stages show only undriven ports (correctly) while the last stage check shows even driven ports as undriven. The RTL has drivers for all of these ports and as shown in step 30 - flow even inserted buffers, but then gave a warning in stage 31. Does anyone know if this is expected or what to do about this ? Thanks