Did France know its other invasion attempts had failed?

Were the French aware that the other invasion attempts had failed?

Yes. They knew the Newcastle and Irish operations had failed, yet continued with the Welsh expedition.

The French knew the other operations had failed when they continued with the Welsh expedition. The Newcastle force had turned back in December, and the Irish expedition had collapsed by January. The Welsh landing still went ahead in late February. Its continuation therefore cannot be explained simply by ignorance of the preceding failures.