Due a problem in Intel® Quartus® Prime Pro Edition version 20.2 and earlier, you may see this error during compilation after you migrate a -VG suffix device to a -XG suffix device of Intel® Stratix® 10.
For example, when PWRMGT_SDA is assigned to SDM_IO11 and PWRMGT_SCL is assigned to SDM_IO14 in 1SG280HU2F50E2VG and when you migrate to 1SG280HU3F50E3XG, you may see the following errors.
Error(19989): SDM_IO 11 has conflicting assignments of PWRMGT_SDA and AVSTx8_VALID
Error(19989): SDM_IO 14 has conflicting assignments of PWRMGT_SCL and AVSTx8_CLK