Hi Experts.
During VoLTE call RF conditions are bad but Handover is canceled: S1AP_handover_cancel.
What could be reason for delay SRVCC due to this cancel?

Make sure that SRVCC threshold are not delayed a lot.
And Handover group id is different for VoLTE.

Please can you guide steps needed to check one by one for Huawei?

Check MOs, CELLQCI, Interrathocomgroup, interrathocom, Cellhoparacfg

As @parkarnadeem86 said, first check the group IDs definitions should be proper.
Check CS only SRVCC enabled or CS+PS SRVCC enabled?
For both items, check configuration at CellHOparacfg and make changes accordingly.

For Huawei in SRVCC Feature detailed implementation plan is given.

Interrathoutran and interrathogeran MOs as well.
Also check which event is set for this event B1 or B2.