One way of fixing it

Back in April the British government introduced a Criminal Courts Charge to "make criminals pay". The structure of the charge - £150 if you plead guilty, and £1000 if you are convicted after a "not guilty" plea - created an obvious incentive for poor people to pleased guilty to offences they haven't committed. But the scale of it also creates obvious miscarriages of justice: for a lot of minor offending, the charge will outweigh any appropriate penalty, effectively leading to institutionalised disproportionate punishment. But now UK judges have a solution to that problem: they simply discharge people without conviction:

Magistrates across Britain are letting guilty petty criminals off with no punishment in order to protect them from controversial new court fees, The Independent has learnt.

They are increasingly resorting to a little-known sentencing option called an absolute discharge which registers guilt but hands out no punishment – effectively letting the criminal off.

[...]

Magistrates have no discretion over how much someone has to pay in court charges if they are punished for their crime. But if they grant an absolute discharge then no punishment is given and poorer defendants are protected from paying over the odds for minor offences.

So you have perverse outcomes on both ends: the innocent are forced to plead guilty from fear, while the guilty avoid even having a conviction registered because to do so would result in disproportionate punishment. But I guess that's what happens when the government institutionalises injustice in order to appear "tough on crime".