When performing Romanian Deadlifts (currently RPE of 8-10), I'm pretty much unable to keep my lower back straight after a few reps.
In regular Deadlifts I don't have that issue (probably because the weight is set on the ground for a second or so after each rep). On the Romanian Deadlift however, my back starts to round pretty soon. Although my hamstrings and glutes feel like they could deal a lot more weight (or reps), I then always have to stop in order to not hurt my back longterm.
Is that normal? I'm now training for roughly 1,5 years. What can be done about it?