WB AMR switching to NB AMR in compressed mode

[Jullien]

Dear All,
I'm here for vey urgent question regarding Compressed Mode RT IS/IF HO in Nokia WCDMA16 when we have Single Rab or multi rab with WB-AMR 12.65kbps
I know that compressed mode IS HO to 2G could trigger change from WB to NB AMR and cancel IS HO CM RT could lead to come back to WB AMR.
Does anyone can confirm ? and if it's the same for IS HO RT CM trigger. thanks in advance.