The most appropriate solution for the technician to consider in this situation is Application virtualization.
Application virtualization is a technology that allows applications to run in a virtual environment, which isolates them from the underlying operating system and other applications. This ensures that the application deployment will not affect other legacy applications on the end users' computers1.

Device interference is the most likely cause of the wireless connection dropping or becoming slow.
Interference can come from other wireless devices, microwave ovens, or physical barriers like walls and metal objects. Hidden SSID, Ethernet port flapping, and high ISP latency are not likely to cause this issue.
Wireless interference from other devices can cause a drop in wireless connection speed and stability. In a small office environment, there may be several wireless devices competing for the same bandwidth, causing the issues described. References: CompTIA A+ Certification Exam Core 1 Exam Objectives - 3.7 Given a scenario, troubleshoot wired and wireless networks with appropriate tools

It is designed to protect an organization's network infrastructure and data from unauthorized access, while allowing legitimate traffic to pass through. Firewalls can be configured to enforce security policies that block certain types of traffic, limit access to specific network resources, and prevent attacks such as malware and phishing.
A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. It establishes a barrier between a trusted internal network and an untrusted external network, such as the Internet. Firewalls are used to implement network security policies for an environment by controlling access to the network and protecting it from unauthorized access.
A firewall is used to implement network security policies. It monitors incoming and outgoing traffic based on predetermined security rules and can block traffic that does not meet the defined criteria. References:
CompTIA A+ Certification All-in-One Exam Guide, Tenth Edition by Mike Meyers (Chapter 6, page 243)

DNS stands for Domain Name System and is a service that translates domain names (such as www.example.com) into IP addresses (such as 192.168.1.100) that computers can use to communicate over a network. If the DNS server is offline, users may not be able to access websites or other network resources by using their domain names, even if they are online and reachable by their IP addresses. The technician should check if the DNS server is running and configured correctly, or use an alternative DNS server if possible.
Reference: https://www.comptia.org/training/books/a-core-1-220-1101-study-guide (page 81)

To clean sticking keys on a laptop keyboard, using compressed air is the most effective and safest method.
Compressed air can dislodge and remove crumbs, dust, and other debris from under the keys without risking damage to the keyboard's electronic components or the keys themselves. This approach is non-invasive and widely recommended for keyboard maintenance.
References:
* CompTIA A+ Core 1 (220-1101) Exam Objectives, particularly sections related to maintaining and cleaning computer components and peripherals, which would cover best practices for keyboard cleaning.
* General computer maintenance guidelines, highlighting the use of compressed air as a standard tool for cleaning keyboards and other computer parts where direct contact cleaning is not advisable.