@z06guy there are quite a few related discussions in the Lung Cancer group about this topic.

Please see
- CBD Oil and Immunotherapy drugs Atezolizmab and Bevacizumab ? https://connect.mayoclinic.org/discussion/cbd-oil-and-immunotherapy-druga-atezolizmab-and-bevacizumab/?pg=1#comment-279484
cancer.
– Pembrolizumab (Keytruda), Cannabis and Cannabinoids https://connect.mayoclinic.org/discussion/nivolumabkeytruda-cannabis-and-cannabinoids/
– Cannabis oil and Immunotherapy https://connect.mayoclinic.org/discussion/cannabis-oil-and-immunotherapy/
– Using CBD/THC Oil to fight metastatic lung cancer https://connect.mayoclinic.org/discussion/using-cbdthc-oil-to-fight-metastatic-lung-cancer/

So far research indicates that CBD oil interferes with immunotherapy. Here are some references to consider:
– https://www.oncologynurseadvisor.com/general-oncology/cannabis-reduces-immunotherapy-response/article/688059/
– https://oncologypro.esmo.org/Meeting-Resources/ESMO-2017-Congress/The-effect-of-cannabis-use-on-tumor-response-to-Nivolumab-in-patients-with-advanced-malignancies
– https://www.medicaljane.com/2014/08/28/study-cannabinoids-may-increase-lung-cancers-susceptibilty-to-specialized-killer-cells/