its odd when i say this
but a Twang Badoing is a spring
I used to have it when a spring was a swine for walking out from its stop position on the lower spring plate, A mechanic rectified it after the garage i brought it from did then didnt fix it
The spring probably needs to be a little tighter in the shock to stop it walking
Its DIY'able, but without a decent jack - spring compressors itll be easier to get a garage to just reseat it