Some Z5 compact phones are having touch input problems. Apparently Sony found the cause and an update to fix it is on its way.
"We are aware of*reports of a limited number of customers experiencing touch input issues on their white Xperia™ Z5 Compact devices. By gathering information and analysing returned devices we have found the root cause and will release a new software to improve the user experience on your white Z5 Compact. Other colour versions of the Xperia™ Z5 Compact are not affected by this issue.
The software update will be available on our support software PC Companion and Bridge for Mac from beginning of week 44. The software is rolling out through retail partners with exact timings varying by region and/or operator".
z5 compact touchscreen acting weird - Page 22 - Support forum
"We are aware of*reports of a limited number of customers experiencing touch input issues on their white Xperia™ Z5 Compact devices. By gathering information and analysing returned devices we have found the root cause and will release a new software to improve the user experience on your white Z5 Compact. Other colour versions of the Xperia™ Z5 Compact are not affected by this issue.
The software update will be available on our support software PC Companion and Bridge for Mac from beginning of week 44. The software is rolling out through retail partners with exact timings varying by region and/or operator".
z5 compact touchscreen acting weird - Page 22 - Support forum