I’m thinking the mix in Canada on bottles might be ones bottled in or mainly for the US market? I guess there’s no requirement to use British English spellings on English labels of stuff sold in Canada, in contrast to regulatory requirements for some things to also be in French.
Seems from answers that ‘soya’ has eroded in Canada. Modern Canadians usually use British spelling (labour not labor, though OTOH Canadian Tire not Canadian Tyre) but American 20th century-type technical terminology (elevator, trunk, gasoline rather than lift, boot, petrol etc; information age technical terminology is pretty much uniform in the English speaking world). This case is sort of in between, being a spelling difference in basically the same word, but which makes an actual difference in the sound.