We swapped and lubricated and I feel it is a bit more stable now. Will try for some time before deciding if there is something wrong still. I bought it over the internet and there is probably enough warranty, but to send it off to UK from EU and back during the combo of pandemic, world wide shopping spree and postal companies + customs doing their best to fail makes it less attractive. Might have to pay shipping. Not sure. So if it boils down to new tubes, I would probably buy a new set and keep these in reserve.