How to avoid cream breaking / splitting in oven?
The splitting of cream depends a lot on the ratio of fat to water in the sauce, and can be influenced through stabilizers. Some possible reasons for the change are: 


the chicken or the bacon of your childhood might have exuded less liquid. Nowadays, chicken meat gets injected with water for "plumpness", and that water seeps out in the oven. The same happens with bacon. 
the chicken of your childhood might have been fattier. Due to customer preference and economic pressure, today's food animals are raised to have lower amounts of fat than several decades ago. 
your mother might have been using a different recipe, or might have stabilized the cream somehow. This can be done with packages of "whipped cream stabilizer" from the supermarket, or adding some flour or starch to the sauce, or using other thickeners. Or she might have been using a brand of curry made with emulsifiers. 


My suggestion for you is to try some kind of thickener. The simplest way would be to dredge the chicken and bacon through flour and see if this helps. If not, consider making a slurry with a tablespoon or two from the cream and some flour or starch, or some emulsifier like xanthan, and folding it into the whipped cream.