it seems you have a real quality problem in your microcells.
have you checked RMS ?
– rxqual avg
– rxlev avg
– timing advance average
– “s” average (radio link counter)
– UL FER
or just by doing a drive test, you’ll see where you’re having a quality issue. have you tried changing frequencies ? deactivate DL power control ? deactivate amr ?
In your situation, the t inhibit will work very well, as i explained earlier… but it is just hidding the problem, not fixing it.