Level UL and Better Cell HO increase is not a consequence of interference !! It means that your TRX are transmitting with less power than before.
What about UL QUAL HO, DL QUAL HO, UL INTERFERENCE HO, DL INTERFERENCE HO, do you notice anything ?
can you check the value of the PathBalance_avg for those cells ? (can be found in the list of indicators)
Finally, are you saying that the problem occurs in all cells of your network ??
There was an issue with some Alcatel trx (TRADE or TRAGE), but it generates huge amount of HO Quality and a very poor Call Setup Sucess Rate and Call Drop Rate. You can check the TRX Assignment Efficiency % (it’s an indicator that you will find in RNO, under “TRX”) per TRX.
But this problem doesn’t lead to Level problems and HO pingpong.