SubrahmanyaHegde Hey mate,
One draining faster the other is normal. When earbuds use a master-slave connection, one earbud (the master) is responsible for handling the primary tasks, such as connecting to the device and transmitting audio signals to the other earbud (the slave). This extra workload causes the master earbud to consume more battery, leading to faster drain compared to the slave earbud, which primarily receives audio signals.
To your point regarding them not charging to 100%. I’d suggest logging a support case. Go to your Nothing X app, click the menu button and click support, then provide all the context you have including any troubleshooting steps you’ve taken.