Flight price more expensive when redeeming eVoucher?

[gseb4]

I’m searching for flights from LHR to Lyon and for some reason the booking page when redeeming eVouchers is coming up with higher prices than when using the “standard” search on the homepage.

Example – LHR to LYS, 1 adult one-way flight on 8 August:
Booking through homepage: 2 direct flights available for £138 and £213 (lowest fares, hand-baggage only)
Booking through the “Save with a Companion or eVoucher” link just below: same 2 flights are now £175 and £272

Weird thing is I’m not able to replicate this discrepancy through any other destinations. Tried a handful like Marseille, Paris, Milan – but they all show the same prices on both booking systems.. Leading me to think it might be a technical glitch? What legitimate reason would BA have for increasing prices for voucher redemptions on this specific route?

Anyone else seen this before? Any workarounds to book with an eVoucher at the lower price?

[BA Flyer IHG Stayer]

Is this the website or the app?

TBH I do almost all of my bookings via the app where the ability to add vocher code comes after you select flights and get the price.

[gseb4]

Thank you! I was using the desktop website on my PC, as I always do when booking tickets.
I was indeed able to book the flight at the same lower price through the app, adding the eVoucher code in the process.