I can't urge you strongly enough to deal with any outstanding issues or disputes AS SOON AS POSSIBLE! The cumulative effect on you and your business of unresolved issues can be toxic, at worst and time-consuming, at best. It's a time in history to be future-focussed, not dwell on past differences. On-going relationships with suppliers, customers, landlords, tenants are all important and need to be treated with care.
The pre-Covid 19 strategies and tactics of dealing with disputes may no longer be appropriate or successful in this very altered landscape. The underlying interests of parties may have changed; matters that were previously seen as leverage may well now be a disadvantage. Conflicts rarely remain immutable - some escalate; some decrease in intensity. It really takes a 'fresh eyes' approach to disputes to make sure the amount of time, energy and resources spent on these issues make sense in light of all the other matters we are now facing.
The 'low-hanging fruit' disputes are those you can resolve yourselves. None of us like conflict but avoidance of simple issues allows them to grow into big issues. Just get started: write out the facts of the dispute from your viewpoint including all costs; identify some of the underlying interests or motivations that are important to you - on-going relationship? reputation? future opportunities? saving face?; if you don't resolve the dispute, what will happen next? what will that cost? how will you do that? how long will that take? Then assess how the other party is likely to see the dispute. Putting yourself in the opposing party's shoes may allow you to think of new ways or options to resolving this issue.