Omio is pretty useless. I just checked for Paris to Lyon and it only suggested long journeys by road coaches. So, then I went into filters and put in for direct trains- search - and it still failed to offer me the high seed trains that operate on this route.
Then I tried Newport in south Wales (UK) to Edinburgh and again, it only showed me bus/coach options taking around 15 hours and going into central London to change to another coach to head north to Edinburgh. This is completely bonkers way to do such a trip. It can be done by train in around 5 to 6 hours and not going anywhere near London.
https://www.thetrainline.com I find is the best site to use for finding train travel across Europe - though I would not use it for trains in the Britain as https://www.buytickets.scotrail.co.uk will come up with same prices for any train journey in Britain and not charge a commission. (They may do 1 split if it reduces the price).
https://trainsplit.com and https://www.traintickets.com/?/ are also good for trains in Britain only and they find ways of reducing the price of getting from a to b by splitting the ticket if it gets a saving - but charge commission on the amount saved.
