I recently bought ten Strawberry 'Honeoye' Bare Root, soaked the roots in luke-warm water as instructed and left them for 24 hours before potting in a mix of compostable and clay pots.. I used broken terracotta to fill the base of the Spanish pots to prevent the soil from washing away then added the compost with a little plant food and topped with bark. The shoots came out almost immediately and provided lovely green leaf, but within two weeks the leaves started to brown and the shoots died back. New shoots have come through, but the leaves continue to brown and die back. At the start I watered twice a week, but find the soil dries out quickly in my conservatory, so began to water three to four times a week. I think there are signs of rot on the stem. Can they be saved?
Likely yes, it sounds as though you may be being too kind to them. In a temperate climate a greenhouse/conservatory will be warm enough to encourage rots, and if the soil is not free draining then water will hang around too long also encouraging fungi, plus the bark chips are like a comforter with an electric blanket, making things too hot. In field grown berries the straw is added only once the flowers and fruits start to appear and the fruits need to be kept off the dirt.
Ideally you want a sandy gritty free draining soil in a free draining pot out in the fresh air with no mulch and kept on the dry side. Lots of rots can affect strawberries, and while the plants may have been free of problems they can pick up fungi from the soil. Immediate action would be to move them outside and get the bark mulch off and reduce the watering. If they start to perk up then good enough, otherwise remove from soil, wash off, remove any dead material and plant in fresh sandy plain garden soil.