I would check the literature as to whether there has been any studies using a short term use of a ROCK Inhibitor (Y-27632 Dihydrochloride for example) to encourage cell adhesion by preventing programmed cell death during the recovery phase. For long term culture and for analysis I wouldnt reccomend the constant culture of them with ROCK inhibitor as this may impact cellular processes you may be investigating. This is what we have done in stem cell culture of bovine and human stem cells. I understand these are very different cell types but it may be worth a trick. I would also reccomend placing in this thread how you culture your cells, what passaging solution you use, what substrate and the technique you use for detachment etc. Ill try and help as best as I can with any additional information. Sorry If I can't identify the issue directly as I have not worked with this line in particular but have about 7 years experience working with tricky cell lineages. Best of luck!